ChatGPT answers, unedited

If your main goal is competitor referral traffic + top inbound links, I’d look at these tools:

The key distinction

Similarweb is particularly useful when you care about “How much traffic is this competitor getting from this referring site?” Its Incoming Traffic data includes referral domains, traffic volume/share, trends and engagement metrics. Similarweb Knowledge Center Similarweb Knowledge Center

Ahrefs is stronger when the question is “Exactly which pages/sites are linking to my competitor, and which links are worth pursuing?” Its Backlinks report lets you inspect individual referring pages, target URLs, link attributes and historical/new links. Its Best by Links report identifies the competitor pages attracting the most backlinks. Ahrefs Ahrefs

Semrush sits between the two: its Referral dashboard is specifically designed to identify sites sending traffic to competitors, while its broader competitor tools combine referral, organic, paid, social and other traffic channels. Semrush Semrush

What I'd use

If you're doing serious competitor intelligence, I'd use Similarweb + Ahrefs:

1. Similarweb: Find competitors' biggest referral traffic sources.
2. Ahrefs: Investigate those domains and identify the actual pages/links sending authority.
3. Ahrefs: Find competitors' newly acquired links so you can spot new partnerships, PR coverage, directories, affiliates, etc.
4. Semrush: Add it if you also want broader monitoring of competitor traffic channels, keywords, paid campaigns and market trends.

One important caveat: competitor referral traffic is estimated, not first-party analytics. Backlinks are observable much more directly, whereas traffic volume from a referring domain is modeled/estimated.

If you tell me your industry + roughly how many competitors you want to monitor, I can also give you a concrete monitoring setup (tools, dashboards, alerts, and exactly which metrics to track weekly).

Semrush sits between the two: its Referral dashboard is specifically designed to identify sites sending traffic to competitors, while its broader competitor tools combine referral, organic, paid, social and other traffic channels. Semrush Semrush

What I'd use

If you're doing serious competitor intelligence, I'd use Similarweb + Ahrefs:

1. Similarweb: Find competitors' biggest referral traffic sources.
2. Ahrefs: Investigate those domains and identify the actual pages/links sending authority.
3. Ahrefs: Find competitors' newly acquired links so you can spot new partnerships, PR coverage, directories, affiliates, etc.
4. Semrush: Add it if you also want broader monitoring of competitor traffic channels, keywords, paid campaigns and market trends.

One important caveat: competitor referral traffic is estimated, not first-party analytics. Backlinks are observable much more directly, whereas traffic volume from a referring domain is modeled/estimated.

If you tell me your industry + roughly how many competitors you want to monitor, I can also give you a concrete monitoring setup (tools, dashboards, alerts, and exactly which metrics to track weekly).

If your goal is specifically “Which sites send competitors traffic, and which individual pages are linking to them?”, I’d split the tools into two categories:

My picks

1. Ahrefs — best for inbound-link intelligence

ahrefs.com is probably the tool I'd start with if “top inbound links” is the core requirement.

You can see competitors' referring domains, individual backlinks, anchor text, linked pages, and estimated organic traffic to the linking pages/domains. Its Link Intersect feature is particularly useful for finding sites that link to competitors but not you. Ahrefs Ahrefs Help Center

A useful workflow is:

Competitor → Referring domains → sort by traffic → inspect backlinks → identify pages sending the links

Ahrefs also lets you monitor competitors' referring-domain growth over time. Ahrefs

2. Similarweb — best for referral traffic

similarweb.com is the better complement if what you actually care about is “How much traffic is competitor X getting from website Y?”

Its Incoming Traffic/Referral Traffic reports are designed specifically to identify sites sending traffic to competitors, including traffic volume, share, trends, and referring domains. Similarweb Knowledge Center Similarweb Knowledge Center

This distinction matters: Ahrefs primarily tells you about links; Similarweb estimates the traffic generated by those referral sources.

3. Semrush — best single-platform alternative

semrush.com has both sides covered. Its Backlink Analytics gives competitor backlink/referring-domain data, while its Traffic & Market toolkit has a dedicated Referral Dashboard for identifying external sites sending traffic to competitors. Semrush Semrush

Its Backlink Gap is also useful for finding domains linking to competitors but not you. Semrush

What I'd use

If you're building a serious competitor-monitoring setup:

Ahrefs + Similarweb

• Ahrefs: Who links to them? Which pages? How many links? What anchor text? What content attracts links?
• Similarweb: Which referring sites actually appear to send them traffic, and how much?
• Compare the two datasets to distinguish lots of SEO links from links that appear to generate meaningful visits.

If you want one subscription only, I'd lean toward Ahrefs for an SEO/link-building use case, or Semrush if you also want broader competitive traffic/marketing research.

A particularly useful monitoring dashboard

For each competitor, I'd track:

• Top 20 referring domains
• Estimated referral traffic from each domain
• New referring domains this month
• Lost referring domains
• Top individual backlinks
• Competitor pages receiving the most backlinks
• Links shared by 2+ competitors but missing from your site
• Referring domains with high traffic but relatively few links
• New PR/news/media links
• Affiliate/partner/referral sites
• Link growth over time

That gives you much more actionable intelligence than simply tracking competitors' total backlink counts.

You can see competitors' referring domains, individual backlinks, anchor text, linked pages, and estimated organic traffic to the linking pages/domains. Its Link Intersect feature is particularly useful for finding sites that link to competitors but not you. Ahrefs Ahrefs Help Center

A useful workflow is:

Competitor → Referring domains → sort by traffic → inspect backlinks → identify pages sending the links

Ahrefs also lets you monitor competitors' referring-domain growth over time. Ahrefs

2. Similarweb — best for referral traffic

similarweb.com is the better complement if what you actually care about is “How much traffic is competitor X getting from website Y?”

Its Incoming Traffic/Referral Traffic reports are designed specifically to identify sites sending traffic to competitors, including traffic volume, share, trends, and referring domains. support.similarweb.com support.similarweb.com

This distinction matters: Ahrefs primarily tells you about links; Similarweb estimates the traffic generated by those referral sources.

3. Semrush — best single-platform alternative

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter?”, I’d use two tools together rather than expecting one database to do everything.

My recommendation

1. Similarweb — best for referral traffic

If you want to answer “Who is actually sending visitors to my competitor?”, Similarweb is probably the most directly aligned. Its Incoming Traffic reports show referral volume, referring websites, traffic share, trends, and industries. Similarweb Knowledge Center Similarweb Knowledge Center

similarweb.com

2. Ahrefs — best for discovering the actual links

For “Show me the pages/sites linking to my competitor”, Ahrefs is stronger. Site Explorer can show the referring page, destination URL, anchor text, followed/nofollow status, historical links, and referring domains. Ahrefs Ahrefs Help Center

Its Link Intersect is particularly useful: give it your site plus several competitors and it finds domains linking to competitors but not to you. Ahrefs Help Center

ahrefs.com

3. Semrush — best if you want both in one competitive workflow

Semrush's Referral dashboard specifically identifies websites sending traffic to competitors, while its broader Traffic & Market tooling lets you compare referral trends, top sources, and traffic by channel. Semrush Semrush

semrush.com

The workflow I'd use

For each competitor, I'd build a table like:

Referring domain → estimated referral traffic → linking page → competitor landing page → link type → domain authority/quality → date discovered → do we have a comparable opportunity?

Then:

1. Similarweb: identify the top referral sources.
2. Ahrefs: investigate those domains and find the specific pages/links responsible.
3. Ahrefs Link Intersect: find referral/linking domains shared by competitors but missing from your profile.
4. Semrush: monitor changes in referral sources over time and see whether competitors are gaining new traffic channels.

One important distinction: a backlink database doesn't tell you that a link actually sends meaningful traffic. Ahrefs can tell you that a competitor has a link and provide traffic estimates for the linking page/site, while Similarweb is designed around estimated referral traffic itself. Ahrefs Similarweb Knowledge Center

If you can only pay for one: I'd choose Semrush if referral traffic is the primary objective, and Ahrefs if link acquisition/SEO is the primary objective. If this is serious competitor intelligence, Similarweb + Ahrefs is the combination I'd lean toward.

similarweb.com

2. Ahrefs — best for discovering the actual links

For “Show me the pages/sites linking to my competitor”, Ahrefs is stronger. Site Explorer can show the referring page, destination URL, anchor text, followed/nofollow status, historical links, and referring domains. Ahrefs Ahrefs Help Center

Its Link Intersect is particularly useful: give it your site plus several competitors and it finds domains linking to competitors but not to you. Ahrefs Help Center

ahrefs.com

3. Semrush — best if you want both in one competitive workflow

Semrush's Referral dashboard specifically identifies websites sending traffic to competitors, while its broader Traffic & Market tooling lets you compare referral trends, top sources, and traffic by channel.

If your specific goal is “Where are competitors getting referral traffic from, and which inbound links actually matter?”, I’d narrow the field to Similarweb + Ahrefs, with Semrush as the best all-in-one alternative.

My ranking

1. similarweb.com — best for referral traffic

This is my #1 choice if “referral traffic” is the key metric.

Similarweb's Incoming Traffic reports show the websites sending traffic to a competitor, estimated referral volume/share, trends, and referring industries. It can also identify sites sending traffic to competitors but not to you—essentially a prospecting list for partnerships, PR, affiliates, and link acquisition. Similarweb Knowledge Center Similarweb Knowledge Center

For example, you could discover:

Competitor A ← Industry publication X ← 8,000 estimated visits/month

That's different from merely knowing that Publication X has a backlink to Competitor A.

Use Similarweb when you want to answer:
“Which external websites are actually sending my competitors visitors?”

2. ahrefs.com — best for inbound links

For SEO/backlink intelligence, I'd pick Ahrefs.

Its Site Explorer lets you see competitors' referring domains and individual backlinks, and you can sort/filter referring domains by things such as traffic. You can then drill into the specific pages linking to your competitor. Ahrefs Ahrefs

The particularly useful feature is Link Intersect: give it your domain plus several competitors, and it identifies sites/pages linking to competitors but not to you. Ahrefs Help Center

Use Ahrefs when you want to answer:
“Who links to my competitors, which links are valuable, and which opportunities am I missing?”

3. semrush.com — best all-around competitor suite

Semrush is probably the best choice if you don't want to stitch multiple tools together.

Its Traffic & Market toolkit has a dedicated Referral Dashboard for identifying websites that send visitors to competitors, while its broader competitor analysis covers traffic channels, top pages, keywords, backlinks, paid traffic, and more. Semrush Semrush

It's especially attractive if you also care about organic search, paid search, social, content, and competitor monitoring rather than just referrals.

Use Semrush when you want:
“Give me one platform for competitive intelligence.”

4. spyfu.com — good lower-cost option

SpyFu is more heavily oriented toward SEO/PPC competitive research, but it also has competitor backlink research. You can search a competitor's inbound links and filter them by keyword, which can be useful for finding links associated with pages ranking for terms you care about. SpyFu

I'd choose it primarily if budget matters and your broader needs include PPC/keyword intelligence.

What I'd actually use

If you're serious about monitoring competitors, I'd use this combination:

Similarweb → “Where is their referral traffic coming from?”
↓
Ahrefs → “Which specific links/domains are responsible?”
↓
Ahrefs Link Intersect → “Which of those sites link to them but not us?”
↓
Semrush → “What other channels/content are contributing to their growth?”

The important distinction is that referral traffic ≠ backlinks.

A competitor might have 500 backlinks from a particular domain, but those links could generate virtually no visitors. Conversely, one link from a highly relevant publication could send substantial referral traffic even though it's only one backlink. Similarweb is better for estimating the former; Ahrefs is substantially better for mapping the latter.

If you tell me your approximate budget (e.g. <$100/mo, $100–300, or $300+) and whether you're mainly doing SEO, affiliate/partnership outreach, PR, or general competitive intelligence, I can recommend the exact stack and workflow.

For monitoring competitors’ referral traffic sources and top inbound links, you’ll usually want a combination of a traffic intelligence tool and a backlink intelligence tool. No single platform is perfect because referral traffic and backlinks are measured differently. Polytraffic

Best tools by use case

My recommended stack

1. For “Where are competitors getting visitors from?”

Use Similarweb.

Good for questions like:

• “Which blogs, affiliates, directories, or partners send them traffic?”
• “Is their growth coming from referrals, SEO, paid, social, or direct?”
• “Which sites send traffic to multiple competitors?”

Similarweb is particularly useful because it focuses on estimated traffic sources and channel mix rather than just SEO links. Buffer

2. For “Who links to competitors that doesn’t link to us?”

Use Ahrefs.

Look at:

• Referring domains
• Best linked pages
• New backlinks
• Lost backlinks
• Anchor text
• Competitor link intersections

Ahrefs’ Link Intersect workflow is designed specifically to find sites linking to competitors but not to you, which is useful for link-building prospecting. Ahrefs Help Center

3. For a broader competitive intelligence dashboard

Use Semrush.

Useful reports:

• Backlink Gap
• Traffic Analytics
• Organic Competitors
• Keyword Gap
• Referring Domains

Semrush combines SEO, paid search, and competitive research data, so it works well if you want one platform instead of separate tools. Semrush

A practical monitoring workflow

Weekly

• Check Similarweb referral changes: - New referral partners
• Sudden traffic spikes
• New affiliate sources

Monthly

• Run Ahrefs/Semrush backlink comparisons: - New referring domains
• High-authority links gained
• New content attracting links

Quarterly

• Build a competitor link map: - Top 100 referring domains across competitors
• Which publications repeatedly cover them
• Which communities/forums/directories drive attention

If you only want to buy one tool

• Referral traffic focus: Similarweb
• SEO/link-building focus: Ahrefs
• One tool for most marketing teams: Semrush

For a serious competitor-monitoring program, a common setup is Similarweb + Ahrefs: one tells you where audiences come from; the other tells you why competitors are earning authority. Polytraffic ahrefs.com

For monitoring competitors’ referral traffic sources and top inbound links, you’ll usually want a combination of a traffic intelligence tool + a backlink intelligence tool. No single platform is perfect because referral traffic and backlinks are measured differently. Polytraffic

Best tools by use case

My recommended stack

1. For referral traffic monitoring

Use Similarweb.

Good questions it answers:

• “Which websites are sending my competitors visitors?”
• “Are they getting traffic from affiliates, publishers, directories, communities, or partners?”
• “Which referral channels are growing?”

Example workflow:

1. Add 5–10 competitors.
2. Export referral sources monthly.
3. Track new referring domains appearing over time.
4. Identify sources sending traffic to multiple competitors.

Buffer### 2. For finding the links you can replicate

Use Ahrefs.

Look for:

• New backlinks → competitors’ recent PR, partnerships, guest posts
• Best by links → pages that attract authority
• Link Intersect → sites linking to competitors but not you
• Lost backlinks → opportunities where you can replace outdated resources

Ahrefs### 3. For an SEO team that wants one dashboard

Use Semrush.

It’s useful if you want:

• backlink gap analysis
• keyword gap analysis
• paid search monitoring
• broader competitor research in one place

SitePoint## Budget options

• Low budget: Ahrefs Webmaster Tools (for your own sites) + free trials/limited competitor reports from Similarweb or Semrush.
• Small marketing team: Semrush or Ahrefs.
• SEO/link-building focused: Ahrefs + Majestic.
• Growth/strategy team: Similarweb + Ahrefs.

A practical monthly competitor monitoring setup

Create a spreadsheet/dashboard with:

If your main goal is finding partnership, affiliate, PR, and outreach opportunities, I’d prioritize Similarweb + Ahrefs. If your goal is mostly SEO link building, start with Ahrefs alone. Ahrefs Buffer

Yes. For your specific use case—monitoring competitors’ referral traffic sources + identifying their highest-value inbound links—I’d narrow it to three serious options:

1. semrush.com — best overall

This is probably my #1 choice for your exact requirement.

Its Referral dashboard shows the domains sending traffic to competitors, ranks referring sources by estimated traffic, and lets you track whether those sources are growing or declining. Semrush

Its Backlinks tools complement that by showing competitors' referring domains, newly acquired links, important partnerships, and backlink growth. Semrush

Use it when you want to answer:

• Who sends my competitor referral traffic?
• Which referral sources are growing?
• Which publishers/sites link to them?
• What are their newest backlinks?
• Which referring domains should we pursue?
• How does referral traffic compare across several competitors?

It also has broader competitor traffic/channel analysis, including organic, paid, social, referral, email, display, and AI traffic. Semrush

2. similarweb.com — best for referral traffic

If your primary question is "Which websites actually appear to be sending traffic to this competitor?", I'd strongly consider Similarweb.

Its Incoming Traffic report provides referral volume, referral share, referring websites, trends, and competitive referral opportunities. You can identify sites sending traffic to competitors but not to you. Similarweb

This is an important distinction:

Ahrefs/Semrush backlink data:

"This site has a link pointing to Competitor A."

Similarweb/Semrush traffic intelligence:

"This site appears to be sending meaningful visitor traffic to Competitor A."

That's much more useful when you're trying to find partnerships, affiliates, publishers, reviews, directories, and referral opportunities, rather than simply collecting backlinks.

3. ahrefs.com — best for finding valuable links

I'd pick Ahrefs if your real objective is competitor link acquisition/SEO.

Its Site Explorer lets you analyze competitors' backlink profiles, and Ahrefs specifically recommends looking at referring pages with significant organic traffic to find links that have a higher probability of actually sending visitors. Ahrefs Help Center Ahrefs

That's a very useful workflow:

Competitor → backlinks → referring pages → filter for pages with traffic → identify opportunities

So rather than saying "Competitor has 50,000 backlinks," you're finding:

"These 37 pages link to competitors AND themselves have substantial traffic."

Those are generally much more interesting prospects.

What I'd use

If budget allows two tools:

Semrush + Ahrefs is my preferred combination.

• Semrush → competitor traffic/referral intelligence
• Ahrefs → deep backlink analysis and link prospecting

If you only want one, I'd choose Semrush for the broader monitoring use case.

If you're primarily doing link building/SEO, choose Ahrefs instead.

If your main KPI is estimated referral visitors rather than backlinks, choose Similarweb.

A particularly effective monitoring setup

I'd create a competitor list and track these monthly:

1. Top referral domains — who sends competitors traffic?
2. New referral sources — what new partnerships/publications appeared?
3. Fast-growing referrers — which sources are suddenly sending more traffic?
4. Top referring pages — which specific articles/pages link to competitors?
5. High-traffic referring pages — which links are most likely to send actual visitors?
6. Competitor-exclusive sources — sites linking to competitors but not you.
7. Lost backlinks — links competitors lost that you might be able to capture.
8. Referral traffic share — whether competitors are becoming more dependent on particular channels.

Semrush's Sources & Destinations dashboard is particularly useful for the ongoing monitoring piece because it can show where traffic comes from and where visitors go afterward. Semrush

Bottom line: If you tell me roughly how many competitors you want to monitor and whether you're doing this for SEO/link building, affiliate acquisition, PR, or general competitive intelligence, I can recommend the most cost-effective setup and the exact reports/workflow I'd use.

That's much more useful when you're trying to find partnerships, affiliates, publishers, reviews, directories, and referral opportunities, rather than simply collecting backlinks.

3. ahrefs.com — best for finding valuable links

I'd pick Ahrefs if your real objective is competitor link acquisition/SEO.

Its Site Explorer lets you analyze competitors' backlink profiles, and Ahrefs specifically recommends looking at referring pages with significant organic traffic to find links that have a higher probability of actually sending visitors.

That's a very useful workflow:

Competitor → backlinks → referring pages → filter for pages with traffic → identify opportunities

So rather than saying "Competitor has 50,000 backlinks," you're finding:

"These 37 pages link to competitors AND themselves have substantial traffic."

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d shortlist these:

1. Similarweb — best for referral traffic

This is my first choice if you're asking “Which sites actually send my competitors visitors?”

Similarweb's Incoming Traffic reports show referring websites, referral traffic volume/share, trends, industries, and competitive referral opportunities. You can compare your site against multiple competitors and identify sites that send traffic to competitors but not to you. Similarweb Similarweb

It is particularly useful for finding things like:

• Affiliate sites
• Publishers/review sites
• Industry directories
• Partnerships
• News/media sites
• Communities that send meaningful traffic
• Referral sources growing rapidly

similarweb.com

2. Semrush — best overall

Semrush is probably the best single platform if you want both sides of the problem.

Its Referral Dashboard ranks competitors' referring domains by traffic volume, shows traffic share and trends, and lets you compare competitors. Its Backlink Analytics also lets you investigate referring domains, individual links, anchors, and the pages receiving those links. Semrush Semrush

So you can go from:

Competitor → referral source → referring page → competitor landing page → backlink → outreach opportunity

That's a very useful workflow for competitive link acquisition.

3. Ahrefs — best for top inbound links

If by “top inbound links” you mean “show me the actual backlinks that are most valuable and help my competitor rank,” I'd favor Ahrefs.

Site Explorer lets you inspect competitors' backlink profiles, referring websites, high-performing pages, and link changes. It also supports monitoring backlink spikes and finding competitors' most-linked pages. Ahrefs

It's especially strong for questions like:

“Which websites link to three of my competitors but don't link to me?”

or:

“Which pages have attracted the most high-quality links?”

ahrefs.com

4. SpyFu — good lower-cost competitor intelligence

SpyFu is worth considering if you're also interested in competitor SEO + PPC. It provides competitor backlink research and lets you identify backlinks competitors have that you don't. SpyFu SpyFu Help Center

One caveat: SpyFu's backlink data is oriented toward links found on pages indexed in Google's top 100, so I wouldn't use it as your only backlink database. SpyFu Help Center

What I'd use

If budget allows two tools:

Similarweb + Ahrefs

• Similarweb: Who is actually sending competitors traffic?
• Ahrefs: Which inbound links are valuable, authoritative, and worth pursuing?

If you want one platform: Semrush is probably the best compromise because it combines competitor traffic/referral analysis with a substantial backlink research suite. Semrush Semrush

A particularly useful monitoring setup

I'd build a competitor-monitoring sheet/dashboard with these columns:

Competitor | Referring domain | Referral traffic | Traffic growth | Linking URL | Target URL | Domain authority/quality | Link type | First seen | Last seen | You link?

Then monitor new referral domains + new high-value backlinks, rather than trying to track every backlink. That tends to surface actual partnership, PR, affiliate, and link-building opportunities much faster.

If you tell me your industry + roughly how many competitors you want to monitor + monthly budget, I can recommend the best tool/plan combination and a concrete monitoring workflow.

Site Explorer lets you inspect competitors' backlink profiles, referring websites, high-performing pages, and link changes. It also supports monitoring backlink spikes and finding competitors' most-linked pages. ahrefs.com

It's especially strong for questions like:

“Which websites link to three of my competitors but don't link to me?”

or:

“Which pages have attracted the most high-quality links?”

ahrefs.com

4. SpyFu — good lower-cost competitor intelligence

SpyFu is worth considering if you're also interested in competitor SEO + PPC. It provides competitor backlink research and lets you identify backlinks competitors have that you don't.

If your goal is specifically “where are competitors getting referral traffic from, and which inbound links matter most?”, I’d use a combination rather than one tool.

My recommended setup

1. Similarweb → referral traffic intelligence

This is the one I'd prioritize if you're specifically interested in traffic, rather than merely backlinks. Similarweb's Incoming Traffic report shows referral domains, referral volume/share, trends, and competitor comparisons. Similarweb Similarweb

For example, you can discover:

Competitor A ← 18,000 visits/month ← industry publication X
Competitor A ← 11,000 ← affiliate Y
Competitor B ← 7,500 ← review site Z

That's much more useful for partnership/PR/affiliate research than simply knowing that those sites link to the competitor.

similarweb.com

2. Ahrefs → inbound-link intelligence

Use Ahrefs when you want to drill into the actual links: linking page, destination URL, anchor text, dofollow/nofollow, referring domain, historical links, etc. Ahrefs Ahrefs

Its Link Intersect feature is particularly useful: give it your domain + several competitors and it identifies domains/pages linking to competitors but not you. You can compare up to 10 competitors in an analysis. Ahrefs Help Center

ahrefs.com

3. Semrush → ongoing competitive monitoring

Semrush is attractive if you want one broader competitive-intelligence platform. Its Referral Dashboard ranks referring domains by the traffic they send competitors and shows trends and traffic share. Semrush

It also combines this with organic rankings, paid search, traffic trends, and other competitor data. Semrush

semrush.com

If I were building the monitoring workflow

I'd do:

Similarweb
→ identify competitors' top traffic-producing referral domains

Ahrefs
→ identify the specific pages/links generating those referrals or authority

Link Intersect
→ find referral sources competitors have that you don't

Monitor monthly
→ new referring domains
→ lost referring domains
→ biggest increases in referral traffic
→ new links to competitor content
→ publishers linking to multiple competitors
→ high-traffic referring domains that don't link to you

One important distinction: a backlink isn't necessarily a referral source. Ahrefs can tell you that Site X links to your competitor; Similarweb is better suited to estimating whether Site X is actually sending meaningful visitors. That's why the two tools complement each other. Ahrefs Help Center Similarweb

If you only want to pay for one: I'd pick Ahrefs for SEO/link-building, Similarweb for referral-traffic intelligence, and Semrush if you want the broadest all-in-one competitor suite.

If your goal is specifically “Where are competitors getting referral traffic from, and which sites/pages are linking to them?”, I’d use a combination rather than one tool.

Best tools

1. Similarweb — best for referral traffic

If you care about actual estimated visits coming from other websites, this is my first choice.

Similarweb's Incoming Traffic report shows competitors' referring websites, referral volume, traffic share, trends, and engagement. You can also compare multiple competitors side-by-side. Similarweb Similarweb

similarweb.com

Use it to answer:

• Which publishers send my competitor the most traffic?
• Is referral traffic growing or declining?
• Which competitors are getting traffic from a particular publisher?
• Which referral sources send traffic to several competitors but not us?
• What percentage of a competitor's traffic comes from referrals?

Especially useful: finding referral opportunities that SEO backlink tools might miss, because a site can send substantial traffic without necessarily being a high-authority SEO domain.

2. Ahrefs — best for finding the actual links

For “show me exactly which pages link to my competitor”, I'd choose Ahrefs.

Its Referring Domains report identifies the sites linking to a competitor, while the Backlinks report lets you drill down to the individual linking pages. You can filter by dofollow, sort by traffic, examine anchor text, and see historical links. Ahrefs Ahrefs

ahrefs.com

One particularly useful feature is Link Intersect: find domains that link to several competitors but don't link to you. That's essentially a ready-made prospecting list. Ahrefs Help Center

3. Semrush — best if you want both in one platform

Semrush's Referral Dashboard specifically ranks competitor referring domains by the amount of traffic they send and shows trends and referral share. Semrush

semrush.com

I'd lean toward Semrush if you also want competitor SEO, paid search, keywords, traffic trends, and market research in the same subscription.

4. Majestic — excellent specialist backlink database

Majestic is worth considering if backlink analysis is a major part of your workflow. Its Site Explorer provides referring domains, linking URLs, inbound links, and topical authority metrics; it also has historical/new-backlink monitoring. Majestic Majestic

majestic.com

What I'd actually buy

If referral traffic is the priority:

Similarweb + Ahrefs

They complement each other extremely well:

Similarweb:
Competitor → referral domain → estimated visits → traffic trend

Ahrefs:
Competitor → referring domain → exact linking page → anchor → target URL → link type

That lets you distinguish between a site that links to a competitor and a site that actually sends meaningful visitors to the competitor.

A particularly powerful workflow

For each competitor:

1. Pull their top 50–100 referral domains in Similarweb.
2. Pull their top referring domains/backlinks in Ahrefs.
3. Cross-reference the lists.
4. Prioritize domains that: - send significant referral traffic,
5. link to multiple competitors,
6. have relevant audiences,
7. have strong organic traffic themselves,
8. don't currently link to you.
9. Use Ahrefs' Link Intersect to find additional domains shared by competitors. Ahrefs Help Center
10. Monitor the list monthly for new referring domains and newly emerging referral sources.

That gives you much more than a generic backlink report—you get a competitor referral-source intelligence system.

If you tell me your industry + 2–5 competitors, I can also lay out exactly how I'd monitor them (including which tool, reports, filters, and metrics to track).

One particularly useful feature is Link Intersect: find domains that link to several competitors but don't link to you. That's essentially a ready-made prospecting list. Ahrefs Help Center

3. Semrush — best if you want both in one platform

Semrush's Referral Dashboard specifically ranks competitor referring domains by the amount of traffic they send and shows trends and referral share. Semrush

semrush.com

I'd lean toward Semrush if you also want competitor SEO, paid search, keywords, traffic trends, and market research in the same subscription.

4. Majestic — excellent specialist backlink database

Majestic is worth considering if backlink analysis is a major part of your workflow. Its Site Explorer provides referring domains, linking URLs, inbound links, and topical authority metrics; it also has historical/new-backlink monitoring. majestic.com majestic.com

majestic.com

What I'd actually buy

If referral traffic is the priority:

Similarweb + Ahrefs

They complement each other extremely well:

Similarweb:
Competitor → referral domain → estimated visits → traffic trend

If your goal is specifically “Where are competitors getting referral traffic from, and which sites/pages are linking to them?”, I’d narrow the field to Similarweb + Ahrefs, with Semrush as the best all-in-one alternative.

My picks

1. Similarweb — best for referral traffic

This is my first choice if you actually care about traffic generated by each referring website, rather than merely knowing that a backlink exists.

Similarweb's Incoming Traffic reports show competitors' referring websites, referral volume, traffic share, trends, and engagement metrics. You can also compare competitors side-by-side. Similarweb Similarweb

similarweb.com

Example workflow:

Competitor A → Incoming Traffic → sort by referral traffic → identify sites sending meaningful visitors → investigate those sites for partnership/PR/content opportunities.

That's particularly useful because a backlink from a high-authority site isn't necessarily sending meaningful visitors.

2. Ahrefs — best for the actual inbound links

For “show me exactly which pages are linking to my competitors”, I'd choose Ahrefs.

Its Backlinks report lets you see the referring page, target URL, anchor text, link attributes, and historical links. Its Referring Domains report can also be sorted by traffic to identify referring sites that are likely to send substantial visitors. Ahrefs Ahrefs

ahrefs.com

The particularly valuable feature for competitive research is Link Intersect: give it your domain and several competitors and it finds domains/pages linking to competitors but not you. You can compare up to 10 competitors in the analysis. Ahrefs Help Center

That's excellent for building a “competitor links we're missing” list.

3. Semrush — best if you want one platform

Semrush is probably the best choice if you don't want to maintain two subscriptions.

Its Traffic & Market toolkit has a dedicated Referral Dashboard that ranks referring domains by the traffic they send to competitors, shows trends, and shows each source's share of referral traffic. Semrush

It also combines competitor traffic, organic search, paid search, backlinks, audience information, and traffic journeys in the same ecosystem. Semrush Semrush

semrush.com

What I'd actually use

If you're doing serious competitor intelligence, I'd use:

Similarweb → “Who sends them traffic?”

↓

Ahrefs → “Exactly which pages/links are responsible?”

↓

Ahrefs Link Intersect → “Which of those sites link to competitors but not us?”

↓

Prioritize → traffic potential + domain quality + topical relevance + likelihood of getting the link

One important distinction: Similarweb estimates traffic, while Ahrefs is much better for the underlying link graph. So I wouldn't use backlink counts alone as a proxy for referral traffic. Similarweb explicitly provides referral-visit estimates and referring-site traffic data, whereas Ahrefs provides the individual backlink/referring-domain data. Similarweb Ahrefs

If I had to buy just one:

• SEO/link-building focused: Ahrefs
• Growth/marketing/referral traffic focused: Similarweb
• Need both plus broader competitor research: Semrush

If you tell me roughly how many competitors you want to monitor and whether you're more interested in SEO backlinks, PR/partnerships, or actual referral visits, I can also give you a specific monitoring setup and dashboard (including what metrics to track weekly/monthly).

1. Similarweb — best for referral traffic

This is my first choice if you actually care about traffic generated by each referring website, rather than merely knowing that a backlink exists.

Similarweb's Incoming Traffic reports show competitors' referring websites, referral volume, traffic share, trends, and engagement metrics. You can also compare competitors side-by-side. Similarweb Similarweb

similarweb.com

Example workflow:

Competitor A → Incoming Traffic → sort by referral traffic → identify sites sending meaningful visitors → investigate those sites for partnership/PR/content opportunities.

That's particularly useful because a backlink from a high-authority site isn't necessarily sending meaningful visitors.

2. Ahrefs — best for the actual inbound links

For “show me exactly which pages are linking to my competitors”, I'd choose Ahrefs.

Its Backlinks report lets you see the referring page, target URL, anchor text, link attributes, and historical links. Its Referring Domains report can also be sorted by traffic to identify referring sites that are likely to send substantial visitors. Ahrefs Ahrefs

ahrefs.com

The particularly valuable feature for competitive research is Link Intersect: give it your domain and several competitors and it finds domains/pages linking to competitors but not you. You can compare up to 10 competitors in the analysis. Ahrefs Help Center

That's excellent for building a “competitor links we're missing” list.

3. Semrush — best if you want one platform

Semrush is probably the best choice if you don't want to maintain two subscriptions.

Its Traffic & Market toolkit has a dedicated Referral Dashboard that ranks referring domains by the traffic they send to competitors, shows trends, and shows each source's share of referral traffic. Semrush

It also combines competitor traffic, organic search, paid search, backlinks, audience information, and traffic journeys in the same ecosystem. Semrush Semrush

semrush.com

What I'd actually use

If you're doing serious competitor intelligence, I'd use:

Similarweb → “Who sends them traffic?”

↓

Ahrefs → “Exactly which pages/links are responsible?”

↓

Ahrefs Link Intersect → “Which of those sites link to competitors but not us?”

↓

Prioritize → traffic potential + domain quality + topical relevance + likelihood of getting the link

One important distinction: Similarweb estimates traffic, while Ahrefs is much better for the underlying link graph. So I wouldn't use backlink counts alone as a proxy for referral traffic. Similarweb explicitly provides referral-visit estimates and referring-site traffic data, whereas Ahrefs provides the individual backlink/referring-domain data.

If I had to buy just one:

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d narrow the field to Similarweb + Ahrefs, with Semrush as the best all-around alternative.

My picks

1. similarweb.com — best for referral traffic

This is the one I'd choose if the question is:

“Which websites are actually sending my competitors visitors?”

Similarweb's Incoming Traffic reports show competitor referral sources, estimated referral volume, traffic share, trends, engagement, and referring industries. It can also identify sites sending traffic to competitors but not to you—very useful for partnership and acquisition prospecting. Similarweb Similarweb

For example, you could discover:

• Competitor A gets significant traffic from review-site.com
• Competitor B gets traffic from industry-news.com
• Neither source sends meaningful traffic to you
• Those become potential outreach/partnership targets

Best for: referral traffic intelligence, partnerships, affiliates, media coverage, competitive channel analysis.

2. ahrefs.com — best for inbound links

If by “top inbound links” you mean the actual URLs/pages linking to competitors, Ahrefs is probably the strongest choice.

Its Site Explorer lets you see:

• Referring domains
• Individual backlinks
• Linking pages
• Destination pages
• Anchor text
• Dofollow/nofollow
• New and lost links
• Historical backlinks
• Link-authority metrics

You can also filter referring domains by traffic and sort them to identify domains that are both authoritative and actually capable of sending traffic. Ahrefs Ahrefs

A particularly useful workflow is:

Competitor → Referring Domains → Dofollow → sort by traffic → inspect individual links

That gets you much closer to “these are the 50 links I should actually care about” rather than a giant backlink dump.

Ahrefs can also monitor new/lost referring domains and backlinks over time. Ahrefs Help Center

Best for: link building, competitor backlink analysis, finding publications/resources that repeatedly link to competitors.

3. semrush.com — best all-around

Semrush is particularly interesting for your use case because its Referral Dashboard explicitly ranks competitor referring domains by the amount of traffic they send, shows trends, and lets you compare competitors. Semrush

It also combines that with:

• Organic search
• Paid search
• Backlinks
• Traffic trends
• Competitor discovery
• Market/channel analysis

So if you don't want separate tools for SEO + traffic intelligence, Semrush is probably the most convenient single platform. Semrush Semrush

Its backlink tools can also give you competitor backlinks, referring domains, authority, anchor text, and link attributes. Semrush

4. spyfu.com — good if PPC is part of the picture

I'd put SpyFu behind the three above for your specific objective. It's particularly strong when competitor organic + paid search intelligence matters, including identifying competitors based on overlapping keywords and ads. SpyFu Help Center SpyFu Help Center

What I'd actually use

If you're serious about competitive referral monitoring, I'd use:

Similarweb + Ahrefs

They answer two different questions:

Similarweb: “Who is sending my competitor traffic?”
Ahrefs: “Exactly which pages are linking to my competitor, and how valuable are those links?”

Then build a simple competitor-monitoring table like:

The really valuable insight isn't simply “who links to competitors.” It's finding sites that:

1. Link to multiple competitors.
2. Send meaningful referral traffic.
3. Have relevant audiences.
4. Have recently started linking to competitors.
5. Don't link to you yet.

That's where competitive intelligence turns into an actionable acquisition/link-building list.

If you tell me your industry and roughly how many competitors you want to monitor (e.g. 5, 20, 100), I can recommend the most cost-effective setup and a specific monitoring workflow.

What I'd actually use

If you're serious about competitive referral monitoring, I'd use:

Similarweb + Ahrefs

They answer two different questions:

Similarweb: “Who is sending my competitor traffic?”
Ahrefs: “Exactly which pages are linking to my competitor, and how valuable are those links?”

Then build a simple competitor-monitoring table like:

If your goal is specifically “Where are competitors getting referral traffic from?” + “Which sites/pages are linking to them?”, I’d shortlist these:

1. Similarweb — best for referral traffic

If the key question is “Which websites are actually sending visitors to my competitors?”, this is probably my first choice.

Similarweb's Incoming Traffic/Referral reports show referral volume, referring websites, trends, and competitive referral opportunities. You can identify sites sending traffic to competitors but not to you. Similarweb Similarweb

similarweb.com

Use it for:

• Top referring domains
• Estimated referral visits
• Referral traffic share
• Referral trends
• Competitor-vs-you referral gaps
• Finding potential partnerships/affiliate/media opportunities

2. Semrush — best if you want traffic + links together

Semrush is particularly attractive because its Referral Dashboard ranks the domains sending traffic to competitors and shows trends and traffic share. It also identifies the specific competitor pages receiving referral traffic. Semrush

Its backlink tools then let you investigate whether those referral sources are also linking to competitors and examine their backlink profiles. Semrush

semrush.com

I'd choose Semrush if you're building a competitive intelligence dashboard rather than doing pure link research.

3. Ahrefs — best for discovering the actual inbound links

Ahrefs is my pick when “top inbound links” means the actual URLs/pages linking to competitors, rather than merely the websites sending referral traffic.

Its Referring Domains report lets you find domains linking to competitors, filter for dofollow links, sort by traffic, and drill into the individual backlinks. Its Link Intersect feature can also find domains linking to competitors but not you. Ahrefs Ahrefs Help Center

ahrefs.com

It's especially useful for answering:

“Competitor X gets links from 1,000 sites. Which 50 are actually worth pursuing?”

You can evaluate the linking domain, linking page, target URL, anchor text, link type, and estimated traffic. Ahrefs

What I'd actually use

For your specific use case, I'd go:

Similarweb + Ahrefs

• Similarweb: Who is sending competitors visitors?
• Ahrefs: Exactly where are the links, and what pages/anchors are involved?

If you only want one subscription, I'd lean Semrush for the broader combination of competitor traffic + referral analysis + backlink research.

One important distinction: referral traffic and backlinks aren't the same thing. A site can send substantial referral traffic through a link that isn't especially valuable from an SEO perspective, while a high-authority backlink might send virtually no visitors. So combining the two datasets gives you a much better prospecting list.

If you tell me your industry and roughly how many competitors you want to monitor (e.g. 5, 20, 100), I can recommend the most cost-effective setup and a monitoring workflow.

Its Referring Domains report lets you find domains linking to competitors, filter for dofollow links, sort by traffic, and drill into the individual backlinks. Its Link Intersect feature can also find domains linking to competitors but not you. ahrefs.com help.ahrefs.com

ahrefs.com

It's especially useful for answering:

“Competitor X gets links from 1,000 sites. Which 50 are actually worth pursuing?”

You can evaluate the linking domain, linking page, target URL, anchor text, link type, and estimated traffic.

What I'd actually use

For your specific use case, I'd go:

Similarweb + Ahrefs

• Similarweb: Who is sending competitors visitors?
• Ahrefs: Exactly where are the links, and what pages/anchors are involved?

If you only want one subscription, I'd lean Semrush for the broader combination of competitor traffic + referral analysis + backlink research.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links are worth pursuing?”, I’d use a combination of Similarweb + Ahrefs, with Semrush as the best all-in-one alternative.

Best tools

1. Similarweb — best for actual referral traffic

If the question is “Which websites are actually sending my competitor visitors?”, this is probably the strongest choice.

Similarweb's Incoming Traffic reports show referring websites, referral traffic volume/share, trends, industries, and competitive referral opportunities. You can also compare multiple competitors to find sites sending traffic to competitors but not to you. Similarweb Similarweb

similarweb.com

Use it for:

• Top referral domains
• Estimated referral visits
• Referral traffic trends
• Finding sites that refer to multiple competitors
• Identifying potential partnerships/PR/affiliate opportunities

2. Ahrefs — best for the actual backlinks

If you're asking “Which pages/sites link to my competitors, and which links should I try to replicate?”, I'd pick Ahrefs.

Its Site Explorer exposes competitor backlink profiles, referring domains and pages, while Link Intersect lets you find domains/pages linking to competitors but not to you. Ahrefs Ahrefs Help Center

ahrefs.com

Use it for:

• Referring domains
• Individual inbound links
• Anchor text
• Linked-to competitor pages
• New/lost backlinks
• Competitor link intersect
• Finding links you don't have

The important distinction: Ahrefs tells you about links; Similarweb estimates the traffic those referring sites actually generate.

3. Semrush — best all-around option

Semrush has become particularly good for this exact use case. Its Referral Dashboard ranks competitor referral domains by the amount of traffic they send and shows trends and share of referral traffic. Semrush

Its Sources & Destinations report also lets you examine where users come from and where they go afterward. Semrush

semrush.com

I'd choose Semrush if you also want SEO, paid search, organic/social, AI traffic, competitor research, and backlink analysis in one platform. Semrush Semrush

What I'd actually recommend

For serious competitor monitoring:

Similarweb → “Who sends them traffic?”
↓
Ahrefs → “Which specific links/pages generate that opportunity?”
↓
Semrush → “What else are they doing across acquisition channels?”

For example, suppose Competitor A gets traffic from:

• forbes.com
• industrypublication.com
• partner-site.com
• reddit.com
• comparison-site.com

Similarweb helps you determine that industrypublication.com is actually sending meaningful traffic, whereas Ahrefs can tell you exactly which article/page links to the competitor and what the link looks like. That distinction is extremely useful when deciding where to spend outreach/PR resources.

If you only want to buy one

Pick Similarweb if your primary KPI is referral traffic acquisition.

Pick Ahrefs if your primary KPI is SEO/link building.

Pick Semrush if you want one broad competitive-intelligence platform.

One caveat: competitor referral traffic numbers are estimates based on third-party data rather than the competitor's private analytics. Semrush explicitly notes that its Traffic Analytics data isn't taken from a site's internal analytics, and Similarweb similarly provides modeled competitive traffic intelligence. Semrush

If you tell me your industry + 3–5 competitors, I can also give you a concrete competitor referral-monitoring workflow (what to track weekly, which reports to export, and how to identify the 10–20 highest-value referral opportunities).

If your goal is specifically “Where are competitors getting referral traffic from, and which sites are linking to them?”, I’d shortlist these:

1. Similarweb — best for referral traffic

This is probably my #1 choice for your exact use case.

Similarweb's Incoming Traffic reports show the websites sending traffic to competitors, referral volume/share, trends, and referral opportunities. You can also compare multiple competitors side-by-side. Similarweb Knowledge Center Similarweb Knowledge Center

The important distinction is that Similarweb can tell you something closer to:

“Site X sent Competitor A an estimated 42,000 visits last month.”

That's different from a backlink database merely telling you:

“Site X has a link pointing to Competitor A.”

If you're trying to identify partnerships, affiliates, publishers, directories, review sites, communities, etc. that actually drive visitors, Similarweb is particularly useful.

2. Semrush — best all-around

semrush.com is arguably the best single-platform option.

Its Referral Dashboard ranks referring domains by the traffic they send competitors, shows changes over time, referral share, and allows competitor comparisons. Semrush

Then you can combine that with Semrush's backlink, organic-search, paid-search, and competitor-analysis tools. Semrush Semrush

I'd pick Semrush if you want to answer:

“Why is Competitor A growing, and what should we steal/replicate?”

rather than only:

“Who links to Competitor A?”

3. Ahrefs — best for inbound links

ahrefs.com is my pick if backlinks are the priority.

You can investigate competitors' referring domains, backlinks, top linked pages, anchor text, and link growth/loss. Ahrefs specifically positions Site Explorer around competitor backlink profiles and tracking backlink changes. Ahrefs

The key advantage is going deeper than referral traffic:

• Which pages attract links?
• Which domains link repeatedly?
• What are the strongest referring domains?
• Which competitor pages have earned the most links?
• Which links are new/lost?
• What content is attracting links?

That's excellent for building a competitor link-acquisition pipeline.

4. Majestic — best specialist backlink tool

majestic.com is worth considering if you're doing serious SEO/link intelligence. It's particularly focused on backlink analysis and metrics such as Trust Flow and Citation Flow. Majestic

I wouldn't buy it instead of Similarweb if your primary question is referral traffic, though.

What I'd actually use

For a serious competitor-monitoring setup:

Similarweb + Ahrefs

Use Similarweb to find:

Who sends competitors traffic?

Then use Ahrefs to investigate:

What links do those sites have, where are the links, and can we reproduce the opportunity?

For example:

1. Identify 20 competitors.
2. Export their top referral domains from Similarweb.
3. Find domains that send traffic to multiple competitors but not you.
4. Rank those domains by estimated referral traffic.
5. Put the highest-value domains into Ahrefs.
6. Examine the exact backlinks, linked pages, anchor text, and link acquisition dates.
7. Turn the resulting list into outreach/partnership/content opportunities.
8. Monitor the same domains monthly for new competitor links.

That combination is much more actionable than simply tracking a competitor's total backlink count.

If you want just one tool: Semrush for breadth, Similarweb for referral traffic specifically, or Ahrefs for backlinks specifically. Semrush Ahrefs

If you tell me your industry + roughly how many competitors you want to monitor, I can also recommend the most cost-effective setup (including which plan/features you actually need).

Similarweb + Ahrefs

Use Similarweb to find:

Who sends competitors traffic?

Then use Ahrefs to investigate:

What links do those sites have, where are the links, and can we reproduce the opportunity?

For example:

Then you can combine that with Semrush's backlink, organic-search, paid-search, and competitor-analysis tools. Semrush Semrush

I'd pick Semrush if you want to answer:

“Why is Competitor A growing, and what should we steal/replicate?”

rather than only:

“Who links to Competitor A?”

3. Ahrefs — best for inbound links

ahrefs.com is my pick if backlinks are the priority.

You can investigate competitors' referring domains, backlinks, top linked pages, anchor text, and link growth/loss. Ahrefs specifically positions Site Explorer around competitor backlink profiles and tracking backlink changes.

The key advantage is going deeper than referral traffic:

If your goal is specifically “Where are competitors getting referral traffic from, and which sites are linking to them?”, I’d use a combination rather than rely on one tool.

My top picks

1. Similarweb — best for referral traffic

If the question is “Which websites are actually sending my competitor visitors?”, this is probably the first tool I'd buy. Similarweb's Incoming Traffic report shows referring websites, referral visits, traffic share, trends, and competitive referral opportunities. You can also compare multiple competitors. support.similarweb.comwww.semrush.comsupport.similarweb.com

This is particularly useful for discovering things like:

• Competitor gets 8% of traffic from an industry publication
• Competitor is suddenly getting traffic from a new partner
• Several competitors receive traffic from the same publisher
• A referral source is growing rapidly
• Sites that send traffic to competitors but not to you

Similarweb's website traffic checker can also give you a quick starting point. www.similarweb.com

2. Ahrefs — best for “who links to my competitors?”

For the link side, I'd choose Ahrefs. Its Backlinks report lets you inspect competitors' backlinks, including the referring page and destination URL. ahrefs.com

The killer feature for your use case is Link Intersect: enter your domain plus several competitors and find websites that link to competitors but don't link to you. You can analyze up to 10 competitors in an analysis and export the opportunities. help.ahrefs.com

That's excellent for building a prospect list:

Competitor A ← Forbes
Competitor B ← Forbes
Competitor C ← Forbes
You ← no link

That's a very obvious outreach/content opportunity.

3. Semrush — best single-platform compromise

Semrush is particularly interesting if you want both sides in one ecosystem. Its Referral Dashboard ranks competitor referring domains by the amount of traffic they send and provides referral trends, shares, and competitive comparisons. www.semrush.com

Its Backlinks tools then let you investigate the actual links and referring domains behind those relationships. www.semrush.com

What I'd actually use

If you have the budget for two tools:

Similarweb + Ahrefs

Use them for different questions:

Similarweb
→ Who sends competitors traffic?
→ How much traffic?
→ Is it growing?
→ Which referral partners matter commercially?

Ahrefs
→ Who links to competitors?
→ Which specific pages contain those links?
→ Which competitors share the same referring domains?
→ What links do they have that I don't?
→ Which links are worth pursuing?

If you want one tool, I'd lean Semrush for an all-around competitive monitoring workflow.

One important distinction

Don't equate “top backlinks” with “top referral sources.”

A competitor may have a backlink from a huge site that sends almost no visitors. Conversely, a relatively modest industry website might send substantial qualified referral traffic.

So I'd build your monitoring dashboard around both:

Referral intelligence

• Referring domain
• Estimated referral visits
• Referral share
• Traffic trend
• Competitors receiving traffic
• New/lost referral sources

Link intelligence

• Referring domain
• Linking URL
• Competitor destination URL
• Anchor text
• Follow/nofollow
• Domain authority/strength
• Estimated organic traffic
• First/last seen

That combination lets you prioritize links that are both authoritative and capable of sending actual customers, rather than chasing vanity backlink counts. support.similarweb.com

If you tell me your industry + 2–5 competitors, I can also lay out a concrete competitor-referral monitoring setup (what to track weekly/monthly, which reports to export, and how to identify the highest-value referral opportunities).

If your goal is specifically “Which sites send competitors referral traffic?” + “Which inbound links are most valuable?”, I’d use two complementary tools, because estimated referral traffic and backlink intelligence are different datasets.

1. Similarweb — best for referral traffic

similarweb.com

This is the one I'd choose if you're trying to answer:

“Where are Competitor A's visitors actually coming from?”

Its Incoming Traffic / Referrals reports show referring websites, estimated referral visits, traffic share, trends and engagement. You can compare multiple competitors and identify sites that send traffic to competitors but apparently don't send it to you. Similarweb Similarweb

That's substantially different from merely finding backlinks.

Example:
You might discover that a competitor gets 8% of its referral traffic from an industry publication. That's much more actionable than simply knowing that the publication has linked to them.

2. Ahrefs — best for inbound-link intelligence

ahrefs.com

For “show me every important site linking to my competitor”, I'd lean Ahrefs.

You can analyze:

• Referring domains
• Individual backlinks
• Dofollow/nofollow
• Linking pages
• Anchor text
• Competitors' most-linked pages
• Estimated organic traffic of linking domains/pages
• New and lost links
• Historical link growth

Ahrefs specifically lets you sort referring domains by traffic, making it easier to distinguish potentially valuable links from a giant pile of low-value backlinks. Ahrefs Ahrefs

Its Link Intersect feature is particularly useful: find sites linking to several competitors but not you. Ahrefs Help Center

3. Semrush — best if you want one broader platform

semrush.com

Semrush has a Referral Dashboard specifically for identifying websites that send traffic to competitors, while its Backlink Analytics provides referring domains, backlinks, link attributes, anchors and new/lost links. Semrush Semrush

I'd pick Semrush over buying both Similarweb and Ahrefs if you also care heavily about SEO keywords, rankings, paid search and broader competitor research.

What I'd actually recommend

For your use case:

Best two-tool stack:

Similarweb + Ahrefs

Use them for different jobs:

1. Similarweb: “Who is actually sending my competitor visitors?”
2. Ahrefs: “Exactly which pages/domains link to them, and which links look worth pursuing?”
3. Cross-reference the two: prioritize referring domains that appear to both send meaningful traffic and have a strong backlink profile.

That last step is where the analysis gets interesting.

For example, I'd build a competitor-monitoring sheet like:

One important distinction: don't treat “top backlink” as synonymous with “top referral source.” A competitor can have hundreds of links from a domain that send virtually no visitors, while a single link from a niche publication can send substantial referral traffic. Similarweb is much better suited to estimating the former; Ahrefs is much better at uncovering the latter. Similarweb Ahrefs

If you tell me your industry and roughly how many competitors you want to monitor, I can also recommend the cheapest tool stack and a concrete weekly monitoring workflow (including what metrics to track and what alerts to set).

Best two-tool stack:

Similarweb + Ahrefs

If your goal is specifically “Which sites are sending my competitors traffic, and which inbound links matter most?”, I’d use a combination of Similarweb + Ahrefs, with Semrush as the broader all-in-one alternative.

My ranking

1. similarweb.com — best for referral traffic

This is my #1 choice if “referral traffic” is the primary thing you want to monitor.

Its Incoming Traffic/Referral reports show the domains sending traffic to competitors, referral volume/share, trends, and competitive referral opportunities. You can compare competitors side-by-side and identify domains sending traffic to competitors but not to you. Similarweb Similarweb

For example, you could discover:

Competitor A ← Forbes
Competitor A ← industry publication X
Competitor B ← review site Y
Competitor B ← partner Z

…and then prioritize the sources that actually appear to be sending visitors, rather than merely having a backlink.

Best use:
Competitor → Traffic → Referrals → Referring websites → Competitive opportunities

2. ahrefs.com — best for the actual backlink investigation

If you find an interesting referring domain in Similarweb, I'd put the competitor into Ahrefs Site Explorer next.

Ahrefs lets you investigate competitors' backlink profiles, including which websites link to them, their strongest links, link changes, and the pages attracting the most links. Ahrefs

This is particularly useful for answering:

• What exact page contains the link?
• Is it editorial or something low-value?
• Which competitor page earned the link?
• What anchor text was used?
• Is the link followed/nofollow?
• How authoritative/relevant is the referring domain?
• Did the competitor recently acquire the link?
• Are multiple competitors getting links from the same site?

Best use: turn “this site sends my competitor traffic” into “here's the exact link and why they got it.”

3. semrush.com — best all-around alternative

Semrush has become particularly good for this use case.

Its Referral Dashboard ranks domains sending traffic to competitors, showing referral volume, share, and whether sources are growing or declining. Semrush

It also combines this with Traffic Analytics, top pages, SEO, backlink gaps, paid advertising, etc. Semrush

So if you want one platform for:

referrals + backlinks + organic search + paid search + competitor traffic + content

I'd seriously consider Semrush.

4. majestic.com — excellent specialist option

Majestic is more specialized around link intelligence. It offers metrics such as Trust Flow, Citation Flow, Topical Trust Flow and tools for finding competitors' top backlinks and comparing link profiles. Majestic

I'd choose it over the others if you're doing serious link-building research, but not as my first choice if your main question is “where does competitor traffic come from?”

The stack I'd actually use

If you're doing serious competitive SEO, I'd run this workflow:

Similarweb → Ahrefs → Semrush

Step 1 — Find traffic-producing referral sources

Use Similarweb to identify:

• Top referral domains
• Referral traffic volume
• Referral traffic share
• Fast-growing referral sources
• Sources competitors have that you don't
• Referral sources shared by multiple competitors

Similarweb explicitly supports identifying these competitive referral opportunities. Similarweb

Step 2 — Investigate the actual links

Take the interesting domains into Ahrefs and determine:

• Exact linking URL
• Target URL
• Link type
• Link authority
• Anchor text
• First-seen date
• Lost/new links
• Other competitors receiving links from the same domain

Ahrefs is especially strong here because its backlink index is designed for this type of competitive link research. Ahrefs

Step 3 — Find patterns across competitors

This is where Semrush/Ahrefs become really useful.

Suppose you have 5 competitors and discover:

The three sites linking to multiple competitors but not you are often much more interesting than a random competitor backlink.

That's essentially a referral + backlink gap analysis, rather than just counting backlinks.

Bottom line

• Want to know where competitors actually get referral traffic? → Similarweb
• Want to know exactly which links they have and which links are valuable? → Ahrefs
• Want one broad competitive-marketing platform? → Semrush
• Want highly specialized backlink intelligence? → Majestic

If I could only buy two: Similarweb + Ahrefs.

The important distinction is that a backlink isn't necessarily a referral traffic source. Ahrefs is excellent at discovering links; Similarweb is better suited to estimating which external domains are actually sending visitors. Using both lets you separate “they have a link” from “that link appears to matter.” Similarweb Ahrefs

4. majestic.com — excellent specialist option

Majestic is more specialized around link intelligence. It offers metrics such as Trust Flow, Citation Flow, Topical Trust Flow and tools for finding competitors' top backlinks and comparing link profiles. majestic.com

I'd choose it over the others if you're doing serious link-building research, but not as my first choice if your main question is “where does competitor traffic come from?”

The stack I'd actually use

If you're doing serious competitive SEO, I'd run this workflow:

Similarweb → Ahrefs → Semrush

Step 1 — Find traffic-producing referral sources

Use Similarweb to identify:

If your goal is specifically “Where do competitors get referral traffic from, and which inbound links matter most?”, I’d narrow the field to Similarweb + Ahrefs + Semrush. They overlap, but they answer slightly different questions.

My picks

1. Similarweb — best for referral traffic

similarweb.com is probably my first choice if the key question is:

“Which websites are actually sending visitors to my competitors?”

Its Incoming Traffic reports show referring websites, referral volume/share, trends, and comparisons between competitors. You can also identify domains sending traffic to competitors but not to you—very useful for partnership, PR, affiliate, and referral prospecting. Similarweb Similarweb

It also lets you look at the broader channel mix—organic, paid, social, referral, email, etc.—so you can tell whether a competitor's growth is actually being driven by referrals. Similarweb

Use it when: you care about traffic, not merely whether a backlink exists.

2. Ahrefs — best for top inbound links

ahrefs.com is my pick for the complementary question:

“Exactly which pages/domains are linking to my competitors, and which links should I try to replicate?”

Site Explorer exposes competitors' backlink profiles, referring websites, top pages, and link quality. Ahrefs currently reports a very large live backlink index and extensive historical data. Ahrefs

This is particularly useful for finding things like:

• High-authority domains linking to competitors
• Competitor pages attracting lots of links
• Newly acquired backlinks
• Lost backlinks
• Sites linking to several competitors but not you
• Link-building opportunities by topic/page

Use it when: you're turning competitor research into an SEO/link-building pipeline.

3. Semrush — best all-in-one

semrush.com has become particularly interesting for this use case because its Traffic & Market product now has a dedicated Referral Dashboard.

It ranks referring domains by the amount of traffic they send to competitors, shows trends and referral share, and lets you compare competitors. Semrush

Its backlink tools then let you dig into referring domains, individual links, anchors, top linked pages, and new/lost links. Semrush

So if you don't want to maintain two platforms, Semrush is probably the best compromise.

What I'd actually use

If I were setting this up for a competitive-monitoring program:

Similarweb → “Who sends them traffic?”

↓

Ahrefs → “Which links are responsible / worth replicating?”

↓

Semrush → “What else is changing in their acquisition strategy?”

The important distinction is that a backlink ≠ referral traffic. Ahrefs can tell you that example.com links to your competitor, but Similarweb is better suited to estimating whether that source actually sends meaningful visitors. Similarweb explicitly reports referral volume and traffic share from referring websites. Similarweb

A particularly useful workflow

For each competitor, I'd maintain a monthly table like:

That lets you distinguish “lots of backlinks” from “important referral relationships.”

Bottom line: If you can afford only one, I'd choose Semrush for the broadest monitoring setup, Similarweb if referral traffic is the primary KPI, and Ahrefs if your ultimate objective is competitor backlink acquisition.

If you tell me your industry, number of competitors, and approximate budget, I can also recommend the most cost-effective stack (including free/cheap options) and a monitoring workflow.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links actually matter?”, I’d use a combination rather than relying on one tool.

My picks

1. similarweb.com — best for actual referral traffic

This is probably the #1 tool for the specific question you asked.

Similarweb's Incoming Traffic reports show the websites sending traffic to a competitor, along with referral volume, traffic share, trends, and engagement. You can also compare competitors. Similarweb Similarweb

For example, you could discover:

Competitor A gets ~8% of its traffic from referrals, with 35% of that referral traffic coming from X, Y and Z.

That's different from merely knowing that X, Y and Z have backlinks to the competitor.

Best use: identify referral partners, affiliates, publishers, directories, communities, news sites, etc. that are actually sending visitors.

Similarweb also lets you see broader traffic-channel mix and compare competitors. Similarweb

2. semrush.com — best all-around choice

If you want one subscription that covers both referral traffic and SEO backlinks, I'd probably choose Semrush.

Its Traffic Analytics/Referral Dashboard specifically identifies websites sending traffic to competitors. Semrush

Its backlink tools then let you drill down into:

• Referring domains
• Individual backlinks
• Linking pages
• Anchor text
• Authority metrics
• New/lost links
• Competitor backlink gaps

Semrush's Backlink Gap is particularly useful for finding domains linking to competitors but not to you. Semrush

So the workflow becomes:

Similarweb-style question:
“Who sends my competitor traffic?”

→ Semrush backlink question:
“Which specific pages on those sites link to my competitor?”

→ Strategy question:
“Can I get a similar link/partnership?”

3. ahrefs.com — best for deep link research

I'd pick Ahrefs if your primary objective is competitor link building rather than referral-traffic estimation.

Site Explorer lets you examine competitor backlink profiles and see which sites link to them, along with their top-performing pages and search traffic. Ahrefs currently reports a very large live backlink index and extensive historical data. Ahrefs

It's particularly good for questions like:

“What are the 100 most valuable pages linking to my competitor?”

or

“Which websites have recently started linking to them?”

For SEO teams, Ahrefs + Similarweb is an excellent combination.

The important distinction

I'd separate your research into two buckets:

Referral intelligence

“Who is actually sending visitors to my competitor?”

Use Similarweb.

Link intelligence

“Who links to my competitor, from which page, with what anchor text, and how authoritative is that link?”

Use Ahrefs or Semrush.

Those aren't the same thing.

A competitor might have a backlink from a huge publication that sends almost no visitors, while a relatively small industry website could send them substantial referral traffic. Similarweb explicitly distinguishes referral traffic from the broader backlink/referring-domain picture. Similarweb

What I'd buy

• Budget-conscious: Semrush alone
• SEO/link-building focused: Ahrefs
• Referral/partnership/competitive intelligence focused: Similarweb
• Serious competitive research: Similarweb + Ahrefs or Similarweb + Semrush

If you're doing this for lead generation or SEO, I can also give you a practical competitor referral-monitoring setup—including exactly what metrics to track weekly, how to identify high-value referring domains, and how to turn the data into an outreach list.

→ Semrush backlink question:
“Which specific pages on those sites link to my competitor?”

→ Strategy question:
“Can I get a similar link/partnership?”

3. ahrefs.com — best for deep link research

I'd pick Ahrefs if your primary objective is competitor link building rather than referral-traffic estimation.

Site Explorer lets you examine competitor backlink profiles and see which sites link to them, along with their top-performing pages and search traffic. Ahrefs currently reports a very large live backlink index and extensive historical data. Ahrefs

It's particularly good for questions like:

“What are the 100 most valuable pages linking to my competitor?”

or

“Which websites have recently started linking to them?”

For SEO teams, Ahrefs + Similarweb is an excellent combination.

The important distinction

I'd separate your research into two buckets:

Referral intelligence

“Who is actually sending visitors to my competitor?”

Use Similarweb.

Link intelligence

“Who links to my competitor, from which page, with what anchor text, and how authoritative is that link?”

Use Ahrefs or Semrush.

Those aren't the same thing.

A competitor might have a backlink from a huge publication that sends almost no visitors, while a relatively small industry website could send them substantial referral traffic. Similarweb explicitly distinguishes referral traffic from the broader backlink/referring-domain picture.

What I'd buy

If your goal is specifically “Which sites send my competitors traffic, and which inbound links are most valuable?”, I’d use a combination of Similarweb + Ahrefs rather than relying on one tool.

My shortlist

1. similarweb.com — best for referral traffic

This is my #1 pick if “referral traffic” is the primary thing you want to monitor.

Similarweb's Incoming Traffic reports show the domains sending traffic to competitors, estimated referral visits, traffic share, trends, industries, and competitive referral opportunities. You can compare competitors side-by-side. Similarweb Similarweb

For example, you could discover:

Competitor A gets significant traffic from industrypublication.com
Competitor B gets traffic from partner-site.com
You get neither → potential partnership/outreach opportunity.

It also lets you look at overall traffic channels, so you can distinguish whether a competitor's growth is coming from referrals vs. organic search vs. social vs. paid. Similarweb

Best use: “Where are competitors actually getting visitors from?”

2. ahrefs.com — best for top inbound links

If by “top inbound links” you mean the actual backlinks pointing to competitor pages, I'd choose Ahrefs.

Its Site Explorer lets you investigate a competitor's backlink profile, including which websites link to them and the quality of those links, while also showing their top-performing pages and search visibility. Ahrefs

This is particularly useful for questions like:

• Which publications link to my competitor?
• Which competitor pages attract the most links?
• What domains link to 3 competitors but not me?
• Which links are newly acquired?
• Which competitors have the strongest referring-domain profiles?
• What content is attracting links?

Best use: “Who links to competitors, and what can I replicate?”

3. semrush.com — best all-in-one alternative

Semrush is particularly interesting if you want both traffic intelligence and backlink intelligence in one ecosystem.

Its Referral Dashboard ranks competitor referring domains by the amount of traffic they send, shows trends and percentage contribution, and lets you compare multiple competitors. Semrush

Its Backlinks tools then let you investigate competitors' recently acquired links, important referring domains, partnerships, and overall backlink profiles. Semrush

I'd pick Semrush over buying two separate tools if you also care heavily about:

• SEO competitors
• keywords
• PPC
• traffic sources
• content
• backlink gaps
• market/competitor monitoring

4. majestic.com — specialist backlink option

Majestic is worth considering if your team is very link-focused.

Its Site Explorer is specifically designed around incoming-link analysis, while its Compare tool can compare up to 10 domains and identify link opportunities. Majestic

I'd generally choose Ahrefs first for a modern SEO workflow, though.

What I'd actually buy

If you're serious about competitive intelligence:

Similarweb + Ahrefs

Use them for different jobs:

Similarweb
→ “Where is their traffic coming from?”

Ahrefs
→ “Which websites are linking to them, which pages are getting links, and what links should we pursue?”

That's a much better combination than trying to make one tool answer both questions.

A useful competitor-monitoring workflow

For each competitor, I'd maintain a spreadsheet/dashboard with:

1. Top 20 referral domains
2. Estimated referral visits
3. Referral traffic growth/decline
4. New referring domains
5. Lost referring domains
6. Top-linked competitor pages
7. Highest-authority referring domains
8. Domains linking to 2+ competitors but not you
9. New publications mentioning/linking to competitors
10. Referral sources that send traffic and appear commercially relevant

The particularly valuable segment is “links to multiple competitors but not us.” That's where you can turn competitive backlink research into an actual prospecting list.

Bottom line:

• Referral traffic → Similarweb
• Backlinks → Ahrefs
• One-tool compromise → Semrush
• Heavy-duty backlink specialist → Majestic

If you tell me roughly how many competitors you want to monitor and your monthly budget, I can also recommend the most cost-effective setup and explain exactly what I'd track weekly vs. monthly.

Similarweb + Ahrefs

Use them for different jobs:

Similarweb
→ “Where is their traffic coming from?”

Ahrefs
→ “Which websites are linking to them, which pages are getting links, and what links should we pursue?”

That's a much better combination than trying to make one tool answer both questions.

A useful competitor-monitoring workflow

If your goal is specifically “which sites send competitors traffic?” + “which individual pages/links are most valuable?”, I’d use a combination rather than one tool.

My top picks

1. Similarweb — best for referral traffic

This is the one I'd prioritize if you're trying to answer:

“Competitor X gets traffic from these 50 websites. Which ones actually send meaningful visitors?”

Similarweb's Incoming Traffic reports show competitor referral domains, traffic volume/share, trends, and engagement information. Similarweb Similarweb

That's an important distinction from conventional backlink tools: a site can have a backlink without that backlink actually sending meaningful visitors.

Similarweb also lets you compare competitors' overall channel mix and identify the domains driving traffic to them. Similarweb Similarweb

Best for: partnerships, affiliates, publishers, directories, reviews, media, sponsorships, referral partnerships.

2. Semrush — best if you want traffic + SEO in one system

Semrush has a dedicated Referral Dashboard that ranks domains sending traffic to competitors and shows trends and their share of referral traffic. Semrush

Its Traffic & Market tooling also lets you compare competitors' organic, paid, social, referral, email, display and other channels. Semrush

So you can go from:

“Who sends them traffic?” → “What pages are they landing on?” → “Is this competitor also winning organic traffic?” → “Can I replicate the acquisition channel?”

I'd pick Semrush if you don't want to buy two separate platforms.

3. Ahrefs — best for finding and evaluating the actual links

Ahrefs is my pick when the question changes from:

“Who sends them traffic?”

to:

“Show me every important website/page linking to them, and tell me which links I should try to acquire.”

Its Site Explorer exposes competitor backlink profiles, referring domains, linked pages and backlink changes. Ahrefs

Particularly useful is Link Intersect: you can find sites/pages linking to multiple competitors but not you, which creates a ready-made prospecting list. Ahrefs Help Center

Ahrefs also recommends prioritizing backlinks from referring pages that themselves have substantial organic traffic—much more useful than blindly chasing domains with high authority metrics. Ahrefs

What I'd actually do

If you're building a competitor referral-monitoring system, I'd use:

Similarweb → Ahrefs → Semrush

For each competitor, maintain something like:

• Top 50 referral domains
• Estimated referral traffic
• Referral traffic growth/decline
• New referral domains
• Lost referral domains
• Top referring pages
• Top linked-to competitor pages
• Link authority/quality
• Whether the referring site links to you
• Whether multiple competitors receive links from it
• First/last seen date
• Opportunity type: review, directory, affiliate, editorial, partnership, etc.

The really valuable workflow is:

Similarweb identifies the sites actually sending traffic → Ahrefs finds the exact links/pages → Link Intersect identifies sites you're missing → Semrush helps monitor the broader competitor movement.

That prevents a common mistake: treating “competitor has a backlink” as equivalent to “competitor gets valuable referral traffic from that backlink.” Similarweb's referral data is much better suited to the latter, while Ahrefs is substantially stronger for the former. Similarweb Ahrefs

If you only want one

• Referral traffic is the priority: Similarweb
• Backlink acquisition is the priority: Ahrefs
• You want one platform covering both plus SEO/PPC: Semrush
• You are doing serious competitor intelligence: Similarweb + Ahrefs

If you tell me how many competitors you want to monitor and roughly your monthly budget, I can narrow this down to the best 2–3 plans and explain exactly what data you'd get from each.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d use two types of tools together: one for actual/estimated traffic sources and one for SEO backlinks.

My top picks

1. Similarweb — best for referral traffic

This would be my first choice if the question is “Which websites are actually sending competitors visitors?”

Similarweb's Incoming Traffic reports show referring websites, referral traffic volume/share, trends, industries, and competitive referral opportunities. You can also compare competitors side-by-side. Similarweb Support Similarweb Support

similarweb.com

For example, you could discover:

Competitor A → 8.4% of referral traffic from Site X
Competitor B → 3.1% from Site X
You → 0%

That's considerably more actionable than simply knowing that Site X links to your competitor.

Best for: affiliate sites, publishers, SaaS, ecommerce, partnerships, PR, competitor intelligence.

2. Semrush — best all-in-one

Semrush is probably the tool I'd pick if you want referral traffic + backlinks + competitor SEO in one ecosystem.

Its Referral Dashboard ranks referring domains by traffic volume and provides referral share and trends. Its Backlink Analytics then lets you investigate the actual links, referring domains, anchor text, new/lost links, and competitors' link profiles. Semrush Semrush

semrush.com

The useful workflow is:

Traffic Analytics → Referral Dashboard → identify promising referring domains → Backlink Analytics → inspect the actual links → prioritize outreach.

That's why I'd choose Semrush if you're building an ongoing competitive-intelligence process, rather than doing occasional backlink research.

3. Ahrefs — best for “show me every important link”

If by “top inbound links” you primarily mean which pages/sites are linking to competitors, Ahrefs is one of the strongest choices.

It's particularly useful for:

• Referring domains
• Individual backlinks
• New/lost backlinks
• Competitor link gaps
• Anchor text
• Linking pages
• Domain/page authority metrics
• Finding sites that link to competitors but not you

The important distinction is that backlink tools generally tell you about the link, whereas Similarweb/Semrush Traffic Analytics are trying to estimate the traffic generated by that referral.

So I'd use Ahrefs to answer:

“Who links to them?”

and Similarweb to answer:

“Who sends them visitors?”

What I'd actually buy

If you have budget for one tool

Semrush.

It gives you the broadest combination of competitor traffic intelligence, referral analysis, SEO, backlinks, keywords, and competitor monitoring. Its current Traffic & Market toolkit specifically includes referral analysis, top pages, traffic channels, and competitor monitoring. Semrush Semrush

If referral traffic is your #1 priority

Similarweb.

It's much closer to the question you're asking: “Which external sites are sending my competitors traffic?” Similarweb explicitly exposes referring websites, referral volume, traffic share, trends, and competitive referral opportunities. Similarweb Support

If SEO/link building is your #1 priority

Ahrefs.

Use it for finding the actual backlinks and building a competitor link-gap database.

Best two-tool combination

Similarweb + Ahrefs

That's my preferred setup for serious competitive research:

• Similarweb: estimated referral traffic → which sources actually matter
• Ahrefs: backlink database → exactly which pages/links are responsible
• Cross-reference the two → high-value referral opportunities

One important caveat

Don't confuse “top referring domains” with “top backlinks.”

A competitor might have 500 links from a publisher, but only 2 of those links could be responsible for meaningful referral traffic. Conversely, a link with relatively little referral traffic today could be strategically valuable for SEO.

So I'd track both:

Traffic value

• Referral visits
• Referral share
• Growth rate
• Engagement

Link value

• Referring domain
• Linking page
• Link placement
• Authority/quality
• New vs. existing link
• Anchor text
• Destination page

That gives you a much better competitor referral-source monitor than simply exporting their backlink profiles.

If you tell me whether you're SaaS, ecommerce, publisher/media, agency, or another type of business, I can also recommend the best tool stack and a concrete monitoring setup (including what metrics to track weekly).

Similarweb.

It's much closer to the question you're asking: “Which external sites are sending my competitors traffic?” Similarweb explicitly exposes referring websites, referral volume, traffic share, trends, and competitive referral opportunities.

If SEO/link building is your #1 priority

Ahrefs.

Traffic Analytics → Referral Dashboard → identify promising referring domains → Backlink Analytics → inspect the actual links → prioritize outreach.

That's why I'd choose Semrush if you're building an ongoing competitive-intelligence process, rather than doing occasional backlink research.

3. Ahrefs — best for “show me every important link”

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links actually matter?”, I’d use a combination of Similarweb + Ahrefs, with Semrush as the best all-in-one alternative.

My ranking

1. similarweb.com — best for referral traffic

This is my #1 choice if “referral traffic” is the key metric.

You can analyze competitors' incoming referral traffic, including:

• Which domains send them traffic
• Estimated referral traffic volume/share
• Referral trends over time
• Referral industries
• New/trending referral sources
• Which referral sources are sending traffic to competitors but not you

Similarweb explicitly supports comparing incoming referral traffic for competitors. Similarweb Similarweb

The important distinction: Similarweb is estimating actual visits generated by referral sources, whereas a backlink crawler is primarily telling you that a link exists.

2. ahrefs.com — best for top inbound links

If you're asking “Which exact websites/pages link to my competitors, and which ones should I pursue?”, I'd pick Ahrefs.

Its Site Explorer lets you inspect:

• Individual backlinks
• Referring domains
• Dofollow/nofollow
• Domain Rating (DR)
• Linking-page metrics
• Estimated organic traffic of the linking page/domain
• Competitors' most-linked pages
• Historical backlink growth

Ahrefs AhrefsThe killer feature for competitive research is Link Intersect: put in your site plus several competitors and find domains that link to competitors but don't link to you. Ahrefs Help Center Ahrefs Help Center

That's extremely useful for building a prospecting list.

3. semrush.com — best all-around competitor suite

Semrush is probably the best choice if you don't want separate tools.

Its Traffic & Market tools show competitors' traffic channels and referral patterns, while its Backlinks tools give you detailed backlink research. Semrush Semrush

You can essentially ask:

Competitor X gets 12% of traffic from referrals. Who are those referring sites, which ones are growing, and do those sites also link to my other competitors?

Semrush also has historical competitor traffic data, which is useful for monitoring changes rather than doing one-off research. Semrush

What I'd actually use

For a serious competitor-monitoring setup:

Similarweb → “Who sends them traffic?”
↓
Ahrefs → “Which pages/domains link to them?”
↓
Ahrefs Link Intersect → “Who links to them but not us?”
↓
Semrush/Similarweb → “Is that referral source actually valuable/growing?”

That distinction is important. A competitor may have 10,000 backlinks but very little referral traffic from them. Another competitor might have 500 backlinks, but 20 of those links could be sending substantial visitors.

If you only want one tool

I'd choose:

• Referral traffic intelligence: Similarweb
• SEO/backlink intelligence: Ahrefs
• One platform covering both: Semrush

And if you're monitoring competitors continuously, I'd track referring domain + estimated referral visits + link URL + destination page + link date + competitor(s) receiving the link. That gives you a much more actionable competitor referral database than simply counting backlinks.

Semrush is probably the best choice if you don't want separate tools.

Its Traffic & Market tools show competitors' traffic channels and referral patterns, while its Backlinks tools give you detailed backlink research. Semrush Semrush

You can essentially ask:

Competitor X gets 12% of traffic from referrals. Who are those referring sites, which ones are growing, and do those sites also link to my other competitors?

Semrush also has historical competitor traffic data, which is useful for monitoring changes rather than doing one-off research. Semrush

What I'd actually use

For a serious competitor-monitoring setup:

Similarweb → “Who sends them traffic?”
↓
Ahrefs → “Which pages/domains link to them?”
↓
Ahrefs Link Intersect → “Who links to them but not us?”
↓
Semrush/Similarweb → “Is that referral source actually valuable/growing?”

That distinction is important. A competitor may have 10,000 backlinks but very little referral traffic from them. Another competitor might have 500 backlinks, but 20 of those links could be sending substantial visitors.

If you only want one tool

I'd choose:

• Referral traffic intelligence: Similarweb
• SEO/backlink intelligence: Ahrefs
• One platform covering both: Semrush

And if you're monitoring competitors continuously, I'd track referring domain + estimated referral visits + link URL + destination page + link date + competitor(s) receiving the link. That gives you a much more actionable competitor referral database than simply counting backlinks.

For monitoring competitors’ referral traffic sources and top inbound links, you’ll usually want a combination of a traffic intelligence tool and a backlink intelligence tool. No single platform is perfect because referral traffic estimation and backlink discovery rely on different datasets. Polytraffic

Best tools by use case

My recommended stack

1. For “Where are competitors getting visitors from?”

Use Similarweb.

Good for answering:

• “Which sites send my competitor the most referral traffic?”
• “Are they growing through affiliates, publishers, communities, or partnerships?”
• “What channels are increasing month over month?”

Similarweb’s traffic analysis includes channel breakdowns and referral-source insights for competitor domains. Similarweb

2. For “Who is linking to competitors?”

Use Ahrefs Site Explorer.

Good for:

• Finding high-authority referring domains
• Tracking new competitor backlinks
• Discovering link-building opportunities
• Identifying competitor pages that attract links

Ahrefs Site Explorer is specifically built around competitor traffic, pages, and backlink analysis. Ahrefs

3. For a single dashboard

Use Semrush.

Useful features:

• Backlink Analytics
• Backlink Gap (sites linking to competitors but not you)
• Traffic Analytics
• Competitor discovery

Semrush’s backlink tools can surface referring domains, recently acquired links, and competitor link opportunities. Semrush

Workflow I’d use

1. Put your top 5–10 competitors into Similarweb.

• Export top referral sources.
• Look for repeat sources across competitors.
• Put those competitors into Ahrefs or Semrush.

• Sort backlinks by: - Domain Rating / Authority
• Traffic
• New links
• Dofollow links
• Create a prospect list:

• Sites linking to 2+ competitors
• Industry publications
• Review sites
• Partner directories
• Resource pages
• Monitor monthly:

• New referring domains
• Lost important links
• New referral partners
• Competitor PR campaigns

If you only want one tool

• SEO/link building focus: Ahrefs Ahrefs
• Growth/marketing intelligence focus: Similarweb Similarweb
• Marketing team needing SEO + PPC + competitive research: Semrush Semrush

For most teams doing competitor monitoring seriously, the strongest pairing is Similarweb + Ahrefs: one tells you where visitors come from, the other tells you which sites are linking and why. Polytraffic

If your goal is specifically “where are competitors getting referral traffic from?” + “which inbound links matter most?”, I’d use two complementary tool types rather than relying on one.

My top picks

1. Similarweb — best for referral traffic

This is the one I'd pick if your primary question is “which sites are actually sending visitors to my competitors?”

Its Incoming Traffic reports show referring websites, estimated referral visits, traffic share, trends, industries, and competitive referral opportunities. You can also compare multiple competitors and identify sites sending traffic to competitors but not you. Similarweb Similarweb

support.similarweb.com

2. Ahrefs — best for inbound-link intelligence

For the question “who links to my competitors, which pages are they linking to, and which links should I care about?”, I'd choose Ahrefs.

Site Explorer lets you inspect competitor backlinks and referring domains, while Link Intersect finds domains/pages linking to competitors but not to you. You can filter links by things such as authority, traffic, follow/nofollow, and the linking page. Ahrefs Ahrefs Help Center Ahrefs

ahrefs.com

3. Semrush — best if you want one broader competitor platform

Semrush's Traffic & Market tools include a dedicated Referral Dashboard that ranks referring domains by the amount of traffic they send to competitors, shows trends and traffic share, and lets you compare competitor sets. It also combines this with organic, paid, audience, and other competitive data. Semrush Semrush

semrush.com

What I'd actually use

If you're doing serious competitive intelligence, my stack would be:

Similarweb + Ahrefs

Use Similarweb to answer:

“Which external sites are sending my competitors visitors?”

Then use Ahrefs to answer:

“Which of those sites actually link to them, what pages do they link to, and how valuable/replicable are those links?”

That's more powerful than looking at raw backlink counts. For example, a competitor might have 50,000 backlinks, but the interesting opportunities could be the 200 referring domains that both link to them and have meaningful traffic.

Similarweb itself recommends combining its incoming-traffic and referring-domain data to identify domains that both link to a site and drive actual traffic. Similarweb

A particularly useful workflow

For each competitor, I'd track:

• Top referral domains by estimated visits
• Referral traffic growth/decline
• New referral sources
• Domains referring to multiple competitors
• Domains referring to competitors but not you
• Top-linked competitor pages
• Highest-traffic linking pages
• Highest-authority referring domains
• Dofollow vs. nofollow
• First-seen/new backlinks
• Lost backlinks
• Referral sources that also have strong SEO authority

That gives you a much more actionable competitor referral + link opportunity database than simply monitoring “backlinks.”

If I had to pick just one: Ahrefs for SEO/link building; Similarweb if referral traffic itself is the primary KPI.

Its Incoming Traffic reports show referring websites, estimated referral visits, traffic share, trends, industries, and competitive referral opportunities. You can also compare multiple competitors and identify sites sending traffic to competitors but not you. Similarweb Similarweb

support.similarweb.com

2. Ahrefs — best for inbound-link intelligence

For the question “who links to my competitors, which pages are they linking to, and which links should I care about?”, I'd choose Ahrefs.

Site Explorer lets you inspect competitor backlinks and referring domains, while Link Intersect finds domains/pages linking to competitors but not to you. You can filter links by things such as authority, traffic, follow/nofollow, and the linking page. Ahrefs Ahrefs Help Center Ahrefs

ahrefs.com

3. Semrush — best if you want one broader competitor platform

Semrush's Traffic & Market tools include a dedicated Referral Dashboard that ranks referring domains by the amount of traffic they send to competitors, shows trends and traffic share, and lets you compare competitor sets. It also combines this with organic, paid, audience, and other competitive data. Semrush Semrush

semrush.com

What I'd actually use

If you're doing serious competitive intelligence, my stack would be:

Similarweb + Ahrefs

Use Similarweb to answer:

“Which external sites are sending my competitors visitors?”

Then use Ahrefs to answer:

“Which of those sites actually link to them, what pages do they link to, and how valuable/replicable are those links?”

That's more powerful than looking at raw backlink counts. For example, a competitor might have 50,000 backlinks, but the interesting opportunities could be the 200 referring domains that both link to them and have meaningful traffic.

Similarweb itself recommends combining its incoming-traffic and referring-domain data to identify domains that both link to a site and drive actual traffic.

A particularly useful workflow

For each competitor, I'd track:

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d use a combination of Similarweb + Ahrefs, rather than relying on one tool.

1. Ahrefs — my first choice for inbound links

Ahrefs Site Explorer

For your use case, Ahrefs is probably the most useful single tool. Its competitor reports let you see:

• Every/large sets of referring domains
• Individual backlinks and referring pages
• Dofollow vs. nofollow
• Estimated organic traffic of the linking site/page
• New and lost links
• Competitors' most-linked pages
• Which domains link to competitors but not you
• Historical link-growth trends

Its Referring Domains report can even be sorted by estimated traffic, which is particularly useful for separating “lots of backlinks” from “links that could actually send meaningful visitors.” ahrefs.comahrefs.com

The Link Intersect feature is especially valuable: enter your domain plus several competitors and find sites that link to them but not you. help.ahrefs.com

Best workflow:
Competitor → Referring Domains → sort/filter by traffic → inspect individual backlinks → identify repeat linkers → add prospects to outreach list.

2. Similarweb — best for actual referral traffic

Similarweb

If by referral traffic sources you mean “Which websites are actually sending visitors to my competitor?”, I'd put Similarweb ahead of Ahrefs.

It's designed around competitive traffic intelligence rather than just SEO links. You can investigate competitors' traffic mix and referral sources, alongside organic, paid, social, display, email, etc.

That's an important distinction:

Ahrefs: “Who links to them?”
Similarweb: “Which sources appear to be sending them traffic?”

So if competitor A has 5,000 referring domains but competitor B has 500, Similarweb can help you determine whether some of those 500 are disproportionately important traffic sources.

3. Semrush — best all-around competitor intelligence

Semrush Competitor Analysis

Semrush is a good middle ground if you want traffic + SEO + paid + content intelligence in one platform.

Its Traffic Analytics can break competitor traffic down into organic, paid, social, referral, email, display and AI channels. www.semrush.com

I'd choose Semrush over Ahrefs if your competitive research extends beyond links—for example:

• What keywords are growing?
• What paid keywords are competitors buying?
• What channels are driving growth?
• Which pages are attracting traffic?
• What are competitors doing with content/ads?

What I'd actually buy

If you're primarily doing SEO/link acquisition:

Ahrefs → best choice

If you're primarily doing growth/competitive intelligence:

Similarweb → best choice

If you're running a broader marketing team:

Semrush → best all-in-one choice

If budget allows two tools:

Ahrefs + Similarweb

That's the combination I'd recommend.

You can build a competitor monitoring sheet like:

Then use Similarweb to identify high-value referral sources and Ahrefs to drill down into the exact pages/links and find opportunities to replicate them.

One important caveat: competitor “referral traffic” numbers are estimates, not their private Google Analytics data. Ahrefs likewise estimates traffic for linking pages/domains rather than knowing the competitor's actual referral sessions. ahrefs.comahrefs.com

If you tell me what type of business/site you're monitoring (SaaS, ecommerce, media, local, etc.) and roughly how many competitors, I can recommend the cheapest tool stack and an exact monitoring workflow for it.

If your goal is specifically “Which sites send my competitors traffic, and which inbound links should we pursue?”, I’d use two tools together rather than trying to make one do everything.

1. Similarweb — best for referral traffic

If you care about traffic actually being sent, this is my first choice.

Similarweb's Incoming Traffic reports show the sites sending traffic to competitors, estimated referral volume, traffic share, trends, and engagement. You can also compare competitors and identify sites that refer to competitors but not you. support.similarweb.com

Similarweb

Use it for:

• Top referral domains
• Estimated referral visits
• Referral traffic share
• Referral trends
• Competitor-vs-you referral gaps
• Finding potential partners, affiliates, publishers, and media sites

The particularly useful workflow is Competitor A + B + C → Incoming Traffic → “Referral Opportunities.” Similarweb explicitly supports identifying referral partners your competitors receive traffic from but you don't. support.similarweb.com

2. Ahrefs — best for top inbound links

For the actual backlink graph, I'd pick Ahrefs.

Its Referring Domains report lets you see every domain linking to a competitor, filter for dofollow links, and even sort referring domains by the traffic they send. You can then drill into the individual backlinks. ahrefs.com

Ahrefs

The killer feature for competitive research is Link Intersect: give it your domain plus several competitors and it finds sites linking to competitors but not you. help.ahrefs.com

I'd especially monitor:

• New referring domains
• Lost referring domains
• Dofollow links
• High-traffic referring domains
• Competitor links you don't have
• Links to competitors' highest-performing pages
• “Serial linkers” that repeatedly link to a competitor

3. Semrush — best if you want one platform

Semrush is probably the best compromise if you want SEO + competitive traffic intelligence in one subscription.

Its Referral Dashboard ranks referring domains by the amount of traffic they send competitors, shows referral share, and tracks whether those sources are growing or declining. www.semrush.com

Semrush

It's particularly attractive if your competitor monitoring also includes:

• Organic keywords
• Paid search
• Display
• Backlinks
• Traffic channels
• Content
• Competitor discovery

What I'd actually buy

If referral traffic is the priority:

Similarweb + Ahrefs

Similarweb answers “Who is actually sending them visitors?”

Ahrefs answers “Where are their links, and how can we replicate the link acquisition?”

That distinction matters. A site can have a valuable backlink that sends essentially no traffic, while another site might send significant referral traffic through a relatively ordinary-looking link.

If budget only allows one:

Ahrefs if you're primarily SEO/link-building focused.
Similarweb if you're primarily growth/competitive-intelligence focused.
Semrush if you want the broadest single-platform coverage.

One important caveat

None of these tools gives you your competitors' first-party Google Analytics data. Referral traffic numbers are estimates, while backlink indexes are based on crawled/discovered links. Similarweb, for example, provides estimated visits and referral shares rather than your competitor's private analytics. docs.similarweb.com

For a serious competitor-monitoring setup, I'd therefore track both:

Traffic layer: Similarweb → top referral domains → referral share → change over time
Link layer: Ahrefs → new/lost backlinks → referring domains → link intersections
Action layer: prioritize domains that are both linking to competitors and demonstrably sending them traffic.

If you give me your industry + 3–5 competitors, I can also suggest exactly what reports/filters to set up and what metrics I'd monitor weekly.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d narrow the field to Similarweb + Ahrefs, with Semrush as the best all-in-one alternative.

1. Similarweb — best for referral traffic

This is my first choice if you literally want to answer “Which websites are sending my competitor visitors?”

Its Incoming Traffic/Referral Traffic reports show referral domains, estimated traffic volume, traffic share, trends and industry breakdowns. It can also identify sites sending traffic to competitors but not to you—very useful for partnership and acquisition prospecting. support.similarweb.com

Use it for:

• Top referral domains by estimated visits
• Referral traffic trends
• Competitor-vs-competitor referral comparisons
• Finding potential affiliates, publishers and partners
• Seeing whether a competitor's referral traffic is growing

Big caveat: Similarweb is estimating traffic, whereas it isn't showing you the competitor's actual GA4 data.

2. Ahrefs — best for the links themselves

If by “top inbound links” you mean exact pages/sites linking to competitors, Ahrefs is probably the strongest choice.

Its Referring Domains report lets you see domains linking to a competitor, filter for dofollow links, and sort referring sites by estimated organic traffic. You can then drill into the individual backlinks. ahrefs.com

The particularly useful feature is Link Intersect: give it your domain plus several competitors and it finds websites/pages linking to competitors but not to you. help.ahrefs.com

I'd use Ahrefs to answer:

“Competitor X got 40 links this month. Which ones are actually worth pursuing?”

rather than merely:

“Who sends them traffic?”

3. Semrush — best if you want both in one ecosystem

Semrush has a Referral Dashboard specifically designed to show which external websites send traffic to competitors. Its Backlinks tools simultaneously let you investigate recent links, referring domains and important partnerships. www.semrush.com

It's a particularly good choice if you're already using Semrush for:

• SEO
• competitor keywords
• paid search
• traffic analysis
• backlink monitoring

So you don't have to stitch together multiple platforms.

What I'd actually use

For serious competitor intelligence, I'd run this stack:

Similarweb → “Who sends them traffic?”

↓

Ahrefs → “Which links/domains are responsible?”

↓

Ahrefs Link Intersect → “Which of those opportunities don't we have?”

↓

Semrush → “How does this fit with their broader acquisition strategy?”

The distinction is important: a backlink isn't necessarily a meaningful referral source. A competitor might have 500 links from a publication, but only one or two pages may actually generate meaningful visitors. Conversely, a relatively low-authority site could send substantial referral traffic.

My ranking for your specific use case

If referral traffic is the #1 priority:
🥇 Similarweb
🥈 Semrush
🥉 Ahrefs

If inbound links/link building is the #1 priority:
🥇 Ahrefs
🥈 Semrush
🥉 Majestic

If you want one subscription:
Semrush is probably the most balanced.

If you're willing to use two:
Similarweb + Ahrefs is the combination I'd choose.

One especially useful workflow is to build a competitor referral watchlist and track monthly: new referral domains → estimated referral visits → top referring pages → competitor landing page → whether you also have that relationship/link. That turns these tools from research dashboards into an actual competitive-monitoring system.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links are actually worth pursuing?”, I’d use two tools together rather than expecting one platform to do everything.

My ranking

1. Similarweb — best for referral traffic

This is the one I'd prioritize if by “referral traffic” you literally mean traffic competitors receive from other websites, rather than merely backlinks.

Similarweb's Incoming Traffic reports show the websites referring traffic to competitors, including traffic volume, share, trends, and industry breakdowns. support.similarweb.com

For example, you can discover:

Competitor A ← Industry publication X ← 18,000 estimated visits/month
Competitor A ← Review site Y ← 7,500
Competitor A ← Partner Z ← 4,200

That's much more actionable than simply knowing that X/Y/Z have backlinks.

Similarweb also lets you compare competitors' overall traffic channels and identify top domains driving traffic. www.similarweb.com

Use it for:

• Finding actual referral partners
• Affiliate/referral opportunities
• Competitor PR coverage
• Industry publications sending traffic
• Monitoring whether referral sources are growing or declining

2. Ahrefs — best for top inbound links

For the backlink side, I'd pick Ahrefs.

Its Site Explorer/Backlinks reports let you see which pages and domains link to a competitor, link type, referring domains, authority metrics, and estimated organic traffic of the linking page/domain. ahrefs.com

The particularly useful feature is Link Intersect: give it your domain plus several competitors and it identifies domains/pages that link to competitors but don't link to you. help.ahrefs.com

That's essentially a ready-made prospecting list:

Competitors A + B + C → 127 sites link to them → 34 don't link to you → prioritize 12 high-value prospects.

Ahrefs can also show your competitors' most-linked pages, which is useful for figuring out what kind of content earns links. support.similarweb.comwww.similarweb.comahrefs.comwww.semrush.comwww.semrush.com

Use it for:

• Top inbound links
• Referring domains
• New/lost backlinks
• Competitor link velocity
• Link-gap analysis
• Finding pages worth replicating
• Finding high-authority outreach prospects

3. Semrush — best if you want both in one ecosystem

Semrush has become particularly relevant to this use case because its Traffic & Market toolkit includes a Referral Dashboard that ranks competitor referring domains by the traffic they send, including trends and share of referral traffic. www.semrush.com

Its broader Traffic Analytics also breaks competitors' traffic into organic, paid, social, referral, email, display, and other channels. www.semrush.com

So if you already use Semrush for SEO/PPC research, I'd probably not buy another platform immediately.

What I'd actually buy

If you're serious about competitive intelligence:

Similarweb + Ahrefs

They answer two different questions:

Similarweb:

“Which websites are actually sending my competitors visitors?”

Ahrefs:

“Which websites/pages are linking to my competitors, and which links should I try to acquire?”

That distinction matters. A competitor can have a backlink from a huge site that sends essentially zero referral traffic. Conversely, a relatively modest website can send substantial qualified traffic.

A good monitoring workflow

I'd set up a monthly/weekly dashboard with:

1. Top 20 referral domains for each competitor
2. Referral traffic change vs. previous period
3. New referring domains
4. Lost referring domains
5. Top individual inbound links
6. Traffic/authority of linking domains
7. Links shared by 2+ competitors
8. New domains linking to competitors but not you
9. Competitors' newly linked pages
10. Referral sources that are growing fastest

Then score each opportunity something like:

Opportunity score = referral traffic × relevance × authority × competitor overlap

That gets you much closer to “which links should our team pursue?” rather than producing a giant backlink spreadsheet nobody uses.

If you tell me your approximate budget (e.g. <$200/mo, $500/mo, $1k+/mo) and how many competitors you want to monitor, I can recommend the exact stack and workflow.

If your goal is specifically “where are competitors getting referral traffic from, and which inbound links matter most?”, I’d use a combination of Similarweb + Ahrefs rather than relying on one tool.

1. Similarweb — best for referral traffic

This is the one I'd prioritize if you want to answer:

“Which websites are actually sending visitors to my competitor?”

Similarweb's Incoming Traffic reports show referring websites, traffic volume/share, trends, and industry information. It specifically lets you identify sites sending traffic to competitors but not to you. support.similarweb.com

For example, you could discover:

• Competitor A gets 8% of traffic from industrypublication.com
• Competitor B gets 4% from partner-site.com
• Neither source sends meaningful traffic to you
• Those become potential partnership, PR, affiliate, or content opportunities.

Similarweb Website Traffic Checker

Best metric: estimated referral visits, not simply number of backlinks.

2. Ahrefs — best for finding the actual links

Use Ahrefs when you want to go one level deeper:

“Okay, this site sends traffic to my competitor. Exactly which page contains the link, what anchor text does it use, and where does it point?”

Ahrefs' Backlinks and Referring Domains reports let you examine individual linking pages, target URLs, anchor text, dofollow/nofollow status, historical links, and estimated organic traffic of the linking domain/page. ahrefs.com

Its Link Intersect feature is particularly useful:

Competitor A + Competitor B + Competitor C → sites linking to them but not you.

That's essentially a ready-made prospecting list. help.ahrefs.com

Ahrefs Backlink Checker

3. Semrush — best if you want both in one platform

Semrush has separate Traffic & Market and Backlink Analytics capabilities.

Its Referral Dashboard ranks domains sending traffic to competitors, including referral volume, share, and whether referral traffic is increasing or declining. www.semrush.com

Its backlink database then lets you investigate the actual links and referring domains. www.semrush.com

So if you don't want to maintain two subscriptions, Semrush is probably the best compromise.

Semrush Traffic & Market

What I'd actually use

For a serious competitor-monitoring setup:

Similarweb → discover referral sources
↓
Ahrefs → inspect the actual links
↓
Ahrefs Link Intersect → find sources competitors have that you don't
↓
Track those domains monthly → identify new/lost competitor relationships

The important distinction is that “referring domain” ≠ “referral traffic source.” A competitor can have 500 links from a site that send virtually no visitors. Conversely, one strategically placed link can send substantial traffic.

Ahrefs itself lets you sort referring domains by estimated traffic, which makes it particularly useful for combining SEO value + potential traffic value. ahrefs.comhelp.ahrefs.comwww.semrush.comahrefs.com

My ranking for your exact use case

If referral traffic is the #1 priority:
🥇 Similarweb
🥈 Semrush
🥉 Ahrefs

If inbound links/link-building is the #1 priority:
🥇 Ahrefs
🥈 Semrush
🥉 Similarweb

If you want one platform:
🏆 Semrush

If you can afford two:
🏆 Similarweb + Ahrefs — probably the strongest combination for this particular job.

If you tell me roughly how many competitors you want to monitor (e.g. 5, 20, 100+) and your monthly budget, I can also narrow this down to the best plan/tier and explain what you'd actually get from each.

If your goal is specifically “where are competitors getting referral traffic from?” + “which inbound links should we pursue?”, I’d use two complementary tools rather than one:

1. Similarweb — best for referral traffic

This is the one I'd pick if you care about actual estimated visits coming from competitor referral sources, rather than merely knowing that a competitor has a backlink.

Similarweb's Incoming Traffic report shows referring websites, referral traffic volume/share, trends, and competitive referral opportunities. You can specifically identify sites sending traffic to competitors but not to you. support.similarweb.comdocs.similarweb.comahrefs.comsupport.similarweb.com

For example, you could discover:

Competitor A → 18,000 visits/month from industrypublication.com
Competitor B → 11,000
You → 0

That's much more actionable than simply knowing the publication links to Competitor A.

Similarweb also exposes referral data through its API, including estimated visits, referral share, and month-over-month changes. docs.similarweb.com

Use it for:

• Top referral domains
• Estimated referral visits
• Referral traffic trends
• Competitor-vs-you referral gaps
• Identifying high-value partners/publications
• Monitoring changes over time

2. Ahrefs — best for the actual backlinks

If by "top inbound links" you mean the specific URLs/pages linking to competitors, Ahrefs is probably the strongest choice.

Its Backlinks report lets you see the referring page, anchor text, target URL, historical backlinks, and link attributes. You can filter for dofollow links and other characteristics. ahrefs.com

Its Referring Domains report is particularly useful because you can:

• Find every domain linking to a competitor
• Filter for dofollow
• Sort referring domains by traffic
• Expand a domain to see the individual links
• Compare competitors' referring-domain profiles ahrefs.comsupport.similarweb.com

That gives you the other half of the picture:

Similarweb: "This publication sends them significant traffic."

Ahrefs: "Here is the exact article/page where the link exists."

That's a very powerful combination for link prospecting.

3. Semrush — best if you want one broader platform

Semrush has a dedicated Referral Dashboard for competitor research. It shows referring domains, referral traffic trends, traffic share, and changes in referral sources. www.semrush.com

Its Backlinks tools then let you investigate competitors' recently acquired links, referring domains, and important partnerships. www.semrush.com

It's particularly attractive if you're already using Semrush for:

• Organic keywords
• Competitor discovery
• Content gaps
• Paid search
• Traffic analytics
• Backlinks
• Ongoing competitor monitoring

Semrush's Traffic & Market product also combines traffic sources, top pages, referral patterns, and broader competitor traffic intelligence. www.semrush.com

What I'd actually buy

If you have budget for two:
Similarweb + Ahrefs

That's the best pairing for your specific use case.

If you want one platform:
Semrush is probably the most convenient compromise.

If SEO/link building is the primary objective:
Ahrefs alone.

If competitive intelligence/traffic acquisition is the primary objective:
Similarweb alone.

The monitoring workflow I'd recommend

Don't just make a static list of competitor backlinks. Set up a recurring process:

1. Similarweb: track competitors' top referral domains and changes in referral traffic.
2. Ahrefs: investigate those domains and find the exact linking pages.
3. Prioritize: rank opportunities by estimated referral traffic + domain quality + relevance + whether they already link to multiple competitors.
4. Monitor new links: look for newly acquired referring domains and newly published competitor links.
5. Track gaps: especially domains linking to 2+ competitors but not you.
6. Separate traffic links from SEO links: a low-authority publication sending 5,000 qualified visitors may be more valuable than a high-DR site sending essentially zero traffic.

The key distinction is that Ahrefs tells you about the link graph, while Similarweb tells you about the traffic flowing through that graph. For competitive referral research, that distinction matters a lot. ahrefs.comsupport.similarweb.com

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links are worth pursuing?”, I’d use a combination rather than one tool.

My picks

1. Similarweb — best for referral traffic

If you specifically want to answer “Which websites are actually sending traffic to my competitors?”, this is probably the strongest choice. Its Incoming Traffic reports show referral domains, traffic volume/share, trends, and engagement, and let you compare competitors. support.similarweb.com

Similarweb

The key distinction: Similarweb is estimating traffic, whereas a backlink crawler tells you that a link exists. Those aren't the same thing.

2. Ahrefs — best for finding the actual links

For SEO/link intelligence, I'd probably make Ahrefs the core tool. Site Explorer lets you inspect competitors' referring domains and individual backlinks, filter for dofollow links, see linking pages, anchor text, target URLs, and identify high-impact links. ahrefs.com

It can also show new/lost referring domains and backlinks over time, which is useful for ongoing competitor monitoring. help.ahrefs.com

Ahrefs

A particularly useful workflow is:

Competitor → Referring Domains → sort/filter by traffic → inspect backlinks → identify domains linking to competitor but not you.

Ahrefs explicitly supports sorting competitor referring domains by traffic and drilling down to the individual links. ahrefs.comwww.semrush.com

3. Semrush — best if you want one broader competitive-intelligence platform

Semrush's Traffic & Market tools cover traffic channels, including referral, while its Backlinks tools let you investigate competitor link profiles. Its Referral Dashboard is specifically designed to identify websites sending visitors to competitors. www.semrush.com

Semrush

I'd choose Semrush over Ahrefs if you also care heavily about paid traffic, display advertising, competitor campaigns, audience research, organic search, and market-level intelligence.

The setup I'd recommend

If you're serious about competitor referral monitoring:

Similarweb + Ahrefs

Use Similarweb for:

• Top referral domains
• Estimated referral visits
• Referral traffic share
• Referral traffic trends
• Competitor-vs-competitor comparisons
• Finding publishers/partners actually driving visitors

Use Ahrefs for:

• Exact referring pages
• Exact target URLs
• Anchor text
• Dofollow/nofollow
• New/lost backlinks
• Referring-domain authority
• Competitor link gaps
• Finding multiple links from the same publisher
• Identifying pages that attract lots of links

That combination lets you distinguish “they have a link from this site” from “this site is actually sending them meaningful traffic.”

One important caveat

Don't treat a competitor's biggest backlink list as your outreach list. A domain can have hundreds of links to a competitor and send essentially zero visitors.

I'd prioritize opportunities roughly like:

Referral traffic × relevance × link authority × likelihood of obtaining the link

For example, a relevant industry publication sending your competitor 2,000 estimated visits/month is much more interesting than 50 random directories that happen to link to them.

If you tell me your industry + roughly how many competitors you want to monitor, I can also recommend the most cost-effective stack and a concrete monitoring workflow (including what metrics to put into a weekly competitor dashboard).

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter most?”, I’d narrow the field to three tools:

1. Similarweb — best for referral traffic

This is my #1 choice if you care about traffic actually being sent by referring sites, rather than merely finding links.

Similarweb's Incoming Traffic reports show the referring websites, referral traffic volume/share, trends, and engagement metrics. It can also identify sites sending traffic to competitors but not to you. support.similarweb.com

So you could discover something like:

Competitor A ← industry publication ← 8,000 estimated visits/month
Competitor A ← partner site ← 3,500 visits/month
Competitor B ← review site ← 2,100 visits/month

That's much more useful for partnership, PR, affiliate, and referral acquisition than simply knowing that a competitor has a backlink.

Similarweb Website Traffic Checker

2. Ahrefs — best for finding the actual links

If your question is more:

“Show me every important site linking to my competitors, the pages they're linking to, and which links I should try to replicate.”

I'd choose Ahrefs.

Site Explorer lets you see competitors' backlinks and referring domains, filter by things like dofollow, domain authority, and referring-site traffic, and identify their most-linked pages. ahrefs.com

A particularly useful workflow is:

Competitor → Referring Domains → sort/filter by traffic → inspect individual links → find domains linking to multiple competitors but not you.

Ahrefs also has Link Intersect specifically for finding sites linking to competitors but not your site. ahrefs.com

Ahrefs Site Explorer

3. Semrush — best if you want monitoring + broader competitor intelligence

Semrush is a strong middle ground. Its Traffic Analytics breaks competitor traffic into organic, paid, social, referral, email, display, and AI channels. Its Referral Dashboard is specifically designed to identify sites sending traffic to competitors. www.semrush.com

Its backlink tools also let you compare domains and inspect referring domains, links, anchors, and top linked pages. www.semrush.com

Semrush Competitor Analysis

What I'd actually use

If budget allows two tools:

Similarweb + Ahrefs

That's the strongest combination because they answer two different questions:

• Similarweb: Who is sending my competitor visitors?
• Ahrefs: Who is linking to my competitor, from exactly which pages, and how valuable is the link?

If you want one platform, I'd pick Semrush for a broader marketing team, or Ahrefs if SEO/link acquisition is the primary objective.

One important distinction: “top inbound links” and “top referral sources” aren't necessarily the same thing. A competitor might have a highly authoritative backlink that sends virtually no visitors, while a smaller partner site could send substantial referral traffic. Ideally, track both link authority and estimated referral traffic.

If you tell me roughly how many competitors you want to monitor and your monthly budget, I can give you a concrete setup (including the cheapest stack that will let you automate the monitoring).

For monitoring competitors’ referral traffic sources and top inbound links, you’ll usually want a combination of a traffic intelligence tool + a backlink intelligence tool. No single platform is perfect because referral traffic and backlinks are measured differently. polytraffic.com

My recommended stack by use case

1. You care about “Where are competitors actually getting visitors from?”

• Use Similarweb first.
• Look for:
  • Top referring domains
  • Referral traffic share
  • Referral traffic growth/decline
  • Industry partnerships and directories
  • Communities sending traffic (forums, newsletters, media sites)

www.similarweb.comahrefs.com

2. You care about “Who links to competitors that doesn’t link to us?”

• Use Ahrefs or Semrush.
• Run:
  • Competitor backlink export
  • Referring domains comparison
  • Link gap analysis
  • New backlinks discovered in the last 30–90 days

www.semrush.comahrefs.com

3. You’re building an ongoing competitor monitoring system
A practical workflow:

Weekly:

• Ahrefs/Semrush → new competitor links
• Similarweb → referral source changes

Monthly:

• Export:
  • Top 100 referring domains
  • Top linked competitor pages
  • Anchor text patterns
  • New partnerships/media mentions

Then classify links:

• PR/media
• Guest posts
• Industry directories
• Communities/forums
• Resource pages
• Partnerships
• Affiliates

If I had to pick only one:

• SEO/link building team: Ahrefs
• Growth/marketing intelligence team: Similarweb
• Agency managing multiple clients: Semrush
• Best combination: Similarweb + Ahrefs (traffic source discovery + backlink execution) www.similarweb.comahrefs.com

A useful tactic is to compare competitor pages with the most referring domains, not just the domains linking to them. Those pages often reveal the content formats, tools, studies, or resources that are attracting links. www.semrush.com

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links actually matter?”, I’d use two tools rather than trying to make one do everything.

My picks

1. Similarweb — best for referral traffic

This is probably the closest match to what you're asking for.

Its Incoming Traffic reports show the websites referring traffic to competitors, including referral volume, traffic share, trends, and referring industries. You can identify sites that send substantial traffic to a competitor but don't send traffic to you. support.similarweb.comhelp.ahrefs.com

I'd use it to answer:

• Which publishers send Competitor A the most traffic?
• Which referral sources are growing?
• Which affiliates/partners appear to be important?
• Which sites refer to several competitors?
• Which referral sources are worth pursuing?

Similarweb's referral traffic documentation

Big advantage: it estimates traffic, rather than merely counting backlinks.

2. Semrush — best all-around option

Semrush has a dedicated Referral Dashboard that ranks competitors' referring domains by the amount of traffic they send, with trends and percentage contribution. www.semrush.com

It also lets you look at the broader traffic mix—organic, paid, social, referral, email, display, and AI traffic—and compare competitors. www.semrush.com

So if you're going to monitor competitors continuously, I'd seriously consider Semrush.

Particularly useful workflow:

Competitor → Referral sources → sort by traffic → identify growing sources → investigate partnership/link → track over time

It can also analyze many competitors in bulk, which is useful if you're monitoring a whole market rather than 2–3 companies. www.semrush.com

3. Ahrefs — best for the actual backlinks

If by "top inbound links" you mean the specific pages linking to competitors, Ahrefs is the one I'd choose.

Its Referring Domains report lets you see the domains linking to a competitor, filter for dofollow links, and even sort referring domains by estimated traffic. You can drill down from a referring domain into the individual backlinks. ahrefs.com

You can also use Link Intersect to find sites that link to multiple competitors but don't link to you. help.ahrefs.com

That's extremely useful for prospecting:

Competitor A ← Forbes
Competitor B ← Forbes
Competitor C ← Forbes
You ← no Forbes link

That's a much stronger prospect than simply finding a competitor with 50,000 backlinks.

Ahrefs Backlink Checker

What I'd actually buy

If budget allows: Similarweb + Ahrefs.

• Similarweb: "Who is actually sending my competitors visitors?"
• Ahrefs: "Exactly which pages/domains are linking to them?"
• Together: "Which links are both valuable for traffic and worth pursuing for SEO?"

If you want one tool only, I'd pick Semrush because it gives you referral traffic + SEO/backlink intelligence + competitor search/paid research in one ecosystem. Its Traffic Analytics specifically covers competitor traffic sources and trends. www.semrush.com

One important caveat: competitor referral numbers are estimates, not their private Google Analytics data. Treat absolute traffic figures as directional; the relative ranking and changes over time are generally more useful.

If you tell me your industry + roughly how many competitors you want to monitor, I can also recommend the best setup and a concrete weekly monitoring workflow.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links are worth pursuing?”, I’d use a combination rather than one tool.

My recommendation

1. Semrush — best overall for your use case

Semrush's Traffic Analytics can show competitor traffic by channel and its Referral dashboard ranks referring domains by the amount of traffic they send, including growth/decline trends. Its Backlinks tool then lets you drill into the actual links, referring domains, anchors, and competitor link profiles. www.semrush.com

This makes it particularly good for questions like:

“Competitor X gets 18% of its referral traffic from these 20 sites. Which of those sites actually link to them, and which pages are they linking to?”

2. Similarweb — best for understanding referral traffic, not just links

Similarweb is probably the strongest choice if the important metric is traffic generated by the referring site rather than merely whether a backlink exists. Its Incoming Traffic report shows referral volume, traffic share, referring websites, trends, and engagement; you can compare competitors side-by-side. www.semrush.comsupport.similarweb.comahrefs.comwww.semrush.com

That's valuable because a competitor might have 500 backlinks from a domain, but only one referring site might actually be sending meaningful visitors.

3. Ahrefs — best for finding the actual backlinks

Ahrefs is my pick if the end goal is link acquisition. Its Site Explorer gives you backlinks and referring domains, and you can drill down to the specific pages/URLs receiving links. ahrefs.com

Use it to identify things like:

• Competitor's newest backlinks
• Highest-authority referring domains
• Links to their highest-performing pages
• Broken/lost competitor links
• Sites linking to several competitors but not you
• Anchor-text patterns

4. Majestic — excellent specialist option

Majestic is worth considering if backlink analysis is a major part of your workflow. It emphasizes referring domains, external inbound links, Trust Flow/Citation Flow, referring IPs and subnets. ja.majestic.com

The stack I'd actually build

If you're doing this seriously, I'd use:

Similarweb → Semrush → Ahrefs

For each competitor:

1. Similarweb: identify the top referral sources by traffic.
2. Semrush: monitor those sources and competitor referral trends.
3. Ahrefs: inspect the actual backlinks from those domains and determine which specific pages/links are worth replicating.
4. Put the results into a recurring spreadsheet/dashboard with:
   • Referring domain
   • Estimated referral visits
   • Number of backlinks
   • Linking page
   • Competitor page receiving the link
   • Authority/quality metric
   • Link type
   • First-seen date
   • Whether we already have a relationship/link
   • Outreach opportunity

If you only want to pay for one: I'd choose Semrush because it covers both sides of your question unusually well—competitor referral traffic and backlink intelligence. Semrush also says its Traffic Analytics uses clickstream data and provides historical competitor data. www.semrush.com

If your primary objective is building a list of high-value sites to acquire links from, I'd choose Ahrefs instead.

If you tell me roughly how many competitors you want to monitor and whether this is SEO/link-building, affiliate, PR, or SaaS competitor intelligence, I can recommend the most cost-effective stack and workflow.

If your goal is specifically “Where are competitors getting referral traffic from, and which inbound links matter?”, I’d use a combination rather than one tool.

1. Similarweb — best for referral traffic

If you want to answer “Which websites are actually sending visitors to my competitor?”, this is the one I'd start with.

Similarweb's Incoming Traffic reports show the websites referring traffic to competitors, including traffic volume, share, trends, and referral domains. support.similarweb.com

For example, you can discover:

• competitor.com ← forbes.com
• competitor.com ← reddit.com
• competitor.com ← partner-site.com
• competitor.com ← affiliate-site.com

The important distinction is that Similarweb estimates traffic generated by those referrals, whereas a backlink database mainly tells you that a link exists.

Use it when: you're looking for partnerships, affiliates, PR placements, directories, communities, publishers, etc.

2. Ahrefs — best for finding the actual links

Ahrefs is my pick when the question becomes:

“Show me exactly which pages are linking to this competitor.”

Its Site Explorer/backlink data is particularly useful for:

• referring domains
• individual referring pages
• new/lost backlinks
• anchor text
• followed/nofollow links
• competitor link gaps
• links pointing to specific competitor pages

This is different from referral-traffic data: a backlink doesn't necessarily generate meaningful traffic, but it can be an excellent SEO/link-building opportunity.

3. Semrush — best if you want both in one platform

Semrush is probably the best choice if you don't want to maintain several subscriptions.

Its competitor tools cover traffic channels, top-performing pages, referral patterns, traffic journeys, keywords, paid campaigns, and backlinks. www.semrush.com

I'd choose Semrush over Ahrefs if your broader competitive-intelligence work includes SEO + paid search + traffic + competitor monitoring, rather than primarily link building.

4. SpyFu — good lower-cost alternative

SpyFu is worth considering if backlinks are your main concern but you don't want to pay for a larger enterprise-oriented platform.

One particularly useful feature is filtering competitor inbound links by keyword, letting you find links from pages that are already ranking for relevant searches. www.spyfu.com

What I'd actually use

For the workflow you're describing:

Similarweb → Ahrefs → Semrush

1. Similarweb: Find the competitor's biggest referral sources.
2. Ahrefs: Investigate the actual pages/sites linking to them.
3. Semrush: Cross-reference those domains against their organic keywords, competitors, paid activity, and overall traffic strategy.

The key is to not treat every backlink as a referral opportunity. I'd prioritize domains where you see both:

high estimated referral traffic + relevant backlink + strong topical fit

Those are much more interesting than a competitor having 10,000 random backlinks.

If you tell me your industry + 2–3 competitor domains, I can also lay out exactly how I'd set up a competitor referral/link-monitoring workflow and what metrics I'd track each week.

If your goal is specifically “Where are competitors getting referral traffic from, and which sites/pages are linking to them?”, I’d shortlist these:

My recommendation

1. Similarweb — best for referral traffic

This is the one I'd choose if the primary question is “Which websites are actually sending my competitors visitors?” Similarweb's Incoming Traffic report shows referral domains, referral volume, traffic share, trends, and engagement, and lets you compare competitors side-by-side. support.similarweb.comahrefs.comwww.semrush.com

You can essentially build a list like:

Competitor → referring site → estimated visits → traffic share → trend

That's much closer to referral traffic intelligence than traditional backlink tools.

2. Ahrefs — best for finding the actual links

For “Show me the pages that link to my competitor”, I'd use Ahrefs. Its Referring Domains report identifies the websites linking to a competitor, while the Backlinks report gets down to individual links. It also has useful workflows for finding competitors' serial linkers—sites that repeatedly link to them. ahrefs.com

This is particularly good if you're turning the research into link-building prospects.

3. Semrush — best if you want one broader competitive-intelligence platform

Semrush's Traffic Analytics breaks competitor traffic down into organic, paid, social, referral, email, display, and AI channels. Its backlink tools also let you analyze competitors and common referring domains. www.semrush.com

So if you're also interested in SEO keywords, PPC, traffic channels, top pages, and backlinks, Semrush is probably the best single subscription.

4. SpyFu — good budget option

SpyFu is especially useful for competitor SEO/PPC research and has a backlink tool that lets you find specific pages linking to competitors and filter opportunities by keyword. www.spyfu.com

The stack I'd use

If this is for serious competitor monitoring, I'd actually combine Similarweb + Ahrefs:

Similarweb → “Who sends them traffic?”
↓
Ahrefs → “What exact links/pages are responsible?”
↓
Your CRM/spreadsheet → “Which opportunities should we pursue?”

For example, if Similarweb shows that IndustrySite.com sends Competitor A significant referral traffic, Ahrefs can help you determine whether that's coming from one major article, dozens of pages, a directory listing, reviews, partnerships, etc.

One important distinction: a backlink ≠ referral traffic. Ahrefs can tell you that a competitor has a link from a site, but Similarweb is better suited to estimating whether that referring site is actually sending meaningful visitors. Similarweb explicitly reports referral visits and traffic share from referring domains. support.similarweb.com

If you tell me how many competitors you want to monitor and roughly what your monthly budget is, I can recommend the best setup (including cheaper/free options) and a monitoring workflow.

If your goal is specifically “Where are competitors getting referral traffic from, and which sites/pages are linking to them?”, I’d narrow it to three serious options:

1. Semrush — best overall

I'd probably start here if you want one platform.

Its Traffic Analytics/Traffic & Market tools show competitor traffic by channel, including referral, and its Referral Dashboard ranks referring domains by the amount of traffic they send. www.semrush.com

Its Backlinks tool then lets you drill into the actual links, compare competitors, identify their top link-acquiring pages, and monitor new/lost links. Semrush says its backlink database can report newly discovered links within roughly an hour on average. www.semrush.com

Best workflow:
Competitor → Referral sources → identify high-value domains → Backlinks → inspect exact pages/links → outreach/content opportunity

2. Similarweb — best for referral traffic

If the important question is “Which sites are actually sending visitors to my competitor?”, Similarweb is particularly strong.

Its Incoming Traffic report provides the referring websites, referral traffic volume/share, trends, industries, and engagement information. You can also compare competitors and identify sites that send traffic to competitors but not to you. www.semrush.comsupport.similarweb.comhelp.ahrefs.comwww.semrush.com

It also has a Backlinks module for analyzing competitors' backlink profiles, so you can move from traffic source → actual links. www.semrush.comsupport.similarweb.com

I'd choose Similarweb over Ahrefs when referral traffic itself—not just SEO authority—is the primary KPI.

3. Ahrefs — best for inbound-link intelligence

For “show me exactly who links to competitors and help me find links I don't have”, Ahrefs is excellent.

Its Backlinks report provides the linking pages, referring domains, link attributes, and estimated organic traffic of the linking page/domain. Its Best by Links report can surface competitors' most-linked pages. ahrefs.com

Even better for competitive research, Link Intersect finds domains/pages linking to your competitors but not to you. help.ahrefs.com

My recommendation

If you're doing competitive intelligence / growth, I'd use:

Similarweb + Ahrefs

• Similarweb → Who sends competitors traffic?
• Ahrefs → Which exact pages/domains link to them?
• Link Intersect → Which of those should we pursue?

If you want to pay for only one, I'd lean:

Semrush → best balance of referral traffic + backlinks + broader competitor research. www.semrush.comwww.semrush.com

One important caveat: competitor referral traffic is estimated, not their private Google Analytics data. So I'd treat the traffic numbers as directional and use the backlink data to validate the underlying opportunities.

If you tell me your industry + roughly how many competitors you want to monitor, I can also recommend the most cost-effective setup and a specific monitoring workflow.

Yes. If your goal is specifically “Where are competitors getting referral traffic from, and which sites/pages are linking to them?”, I’d narrow the field to these:

1. Similarweb — best for referral traffic

Similarweb

This is the one I'd choose if referral traffic is your primary question. Its Incoming Traffic reports show the websites sending traffic to a competitor, estimated referral volume/share, trends, industries, and traffic quality. You can also compare multiple competitors side-by-side. support.similarweb.comahrefs.comsupport.similarweb.com

For example, you can discover:

Competitor A gets significant traffic from examplepublisher.com, while Competitor B doesn't.

That's potentially a partnership, affiliate, PR, or content-placement opportunity.

2. Semrush — best single-tool option

Semrush

Semrush is probably the best choice if you want referral + backlinks + SEO + competitor traffic in one ecosystem.

Its Traffic Analytics breaks competitor traffic into channels including referral, organic, paid, social, email, display and AI traffic. www.semrush.com

Its Backlinks tool lets you compare competitors, analyze referring domains/anchors, find competitors' top link-acquiring pages, and monitor new/lost links. www.semrush.com

My pick if you don't want to maintain multiple tools.

3. Ahrefs — best for finding the actual links

Ahrefs

I'd use Ahrefs when the question changes from:

“Who sends my competitor traffic?”

to:

“Show me the actual pages linking to my competitor so I can pursue similar links.”

Its Backlinks report exposes referring pages, destination URLs, anchor text, link attributes, referring domains, and other filters. It also provides estimated organic traffic for the linking page and referring domain. ahrefs.com

That's particularly useful for building a competitor link-gap list.

4. SpyFu — good budget alternative

SpyFu

SpyFu is worth considering if SEO competitor research is important but you don't want to spend as much. Its backlink tools let you find competitor inbound links and filter toward links that are relevant to particular keywords. www.semrush.comahrefs.comwww.spyfu.comhelp.spyfu.comsupport.similarweb.com

One caveat: SpyFu's backlink database is oriented around backlinks found on pages ranking in Google's top 100, so I wouldn't use it as your only backlink source. help.spyfu.com

What I'd actually use

If I were setting up a competitor-monitoring stack:

Similarweb + Ahrefs would be my preferred combination.

• Similarweb: Who is actually sending competitors referral traffic?
• Ahrefs: Which exact pages/domains are linking to them?
• Semrush: Add it instead if you also need competitor SEO, PPC, keywords, traffic channels, and content research in the same platform.

A useful workflow is:

Competitor → top referral domains → identify high-value referring sites → cross-check their backlinks → find the exact linking page → classify opportunity → monitor new/lost links.

The important distinction is that referral traffic and backlinks aren't the same thing. A competitor can have a huge number of backlinks from sites that send almost no visitors, while a single publisher, affiliate, review site, or community can send substantial referral traffic from only a handful of links. Similarweb is stronger for estimating the former; Ahrefs/Semrush are stronger for investigating the latter. ahrefs.comsupport.similarweb.com

If you tell me your industry and roughly how many competitors you want to monitor, I can recommend the most cost-effective setup (including which plan/features you actually need).

If your goal is to understand where competitors get referral traffic and which websites link to them, no single tool gives a complete picture. The best approach is usually to combine a backlink intelligence platform with a traffic estimation platform.

Here's how the major options compare:

1. Ahrefs (Best overall for inbound links)

Best if you're primarily interested in:

• Who links to competitors
• New backlinks
• Lost backlinks
• Most-linked pages
• Anchor text
• Link growth over time

Strengths:

• One of the largest backlink indexes
• Excellent filtering
• Historical data
• Find links competitors have that you don't

Weaknesses:

• Referral traffic estimates aren't its strongest feature.

Ideal for:

• SEO agencies
• Content marketers
• Link building campaigns

2. Similarweb (Best for referral traffic)

If your real question is:

"Which websites actually send visitors to my competitor?"

This is the strongest platform.

It estimates:

• Referral traffic
• Traffic share
• Top referring websites
• Outbound destinations
• Traffic channels
  • Direct
  • Organic
  • Paid
  • Social
  • Email
  • Referral
  • Display

You can often discover partnerships like:

TechCrunch
Product Hunt
Forbes
Affiliate blogs
Industry associations
Directories
Review sites

It also estimates:

• Visits/month
• Geography
• Audience overlap

3. Semrush (Best all-around marketing intelligence)

Semrush combines both worlds:

• Backlinks
• Referral domains
• Organic keywords
• PPC
• Display ads
• Competitor research

Useful reports:

• Backlink Analytics
• Bulk Analysis
• Traffic Analytics
• Market Explorer

If you're already using Semrush, you may not need another platform.

4. Majestic (Best for link graph analysis)

Majestic is still excellent if you care about:

• Trust Flow
• Citation Flow
• Link neighborhoods
• Authority networks

Less useful for traffic intelligence.

5. SE Ranking (Best value)

A lower-cost alternative that still provides:

• Backlink monitoring
• Competitor comparisons
• Referring domains
• Historical changes

Good for startups or small businesses.

Best free tools

These won't estimate referral traffic very well, but they're useful:

• Google Search (link:, brand mentions)
• Google Alerts
• Bing Webmaster Tools (your own site)
• Cloudflare Radar (limited web insights)

If you want affiliate/referral partners

Use both:

Similarweb

• Find referral sources

then

Ahrefs

• Investigate those referring domains
• Find all linked pages
• Discover similar linking sites

This workflow uncovers affiliate networks, review blogs, directories, sponsorships, and partnerships.

Enterprise options

If budget isn't a concern:

• Similarweb Enterprise
• SparkToro (audience intelligence)
• Demandbase (B2B)
• Crayon (competitive intelligence)

These provide deeper competitive insights beyond SEO.

My recommended combinations

• Best overall: Similarweb + Ahrefs
• Best all-in-one: Semrush
• Best budget: SE Ranking + Similarweb Starter
• Best for agencies: Ahrefs + Similarweb + SparkToro

For specifically monitoring competitors' referral traffic sources and top inbound links on an ongoing basis, Similarweb + Ahrefs is generally the strongest combination: Similarweb identifies where their visitors are coming from, while Ahrefs shows exactly which pages and domains are linking to them and alerts you as those links change.

If your goal is to monitor competitors' referral traffic sources (where their visitors come from) and top inbound links (who links to them), you'll typically need a combination of traffic intelligence and backlink analysis tools. No single tool has perfect visibility, so the strongest setups combine two categories.

Best for referral traffic

If you're trying to answer questions like:

• Which websites send competitors the most visitors?
• Which affiliates are promoting them?
• Which blogs or publications drive traffic?
• Which partner sites refer customers?

then Similarweb is the market leader. It estimates:

• Top referring websites
• Referral categories
• Social traffic sources
• Display ad partners
• Search vs referral vs direct traffic
• Geographic traffic distribution

This is information that backlink tools generally cannot estimate well.

Best for inbound links

For questions like:

• Who linked to my competitor this week?
• Which pages earned the most backlinks?
• What anchor text are people using?
• Which domains have the highest authority?

Ahrefs is widely considered one of the strongest backlink databases.

Useful reports include:

• New backlinks
• Lost backlinks
• Best by links
• Referring domains
• Link growth over time
• Broken backlinks

Semrush offers similar capabilities and adds strong competitive marketing insights.

Best combination

If budget allows:

• Similarweb → referral traffic intelligence
• Ahrefs → backlink intelligence

If you only want one platform:

• Semrush provides a very good balance of referral estimates, backlinks, keyword research, and competitor monitoring.

For ongoing competitor monitoring

A practical weekly workflow is:

1. Track competitors' new backlinks.
2. Monitor newly referring domains.
3. Watch for spikes in referral traffic.
4. Identify new partnerships or affiliate sites.
5. Find publications that mention multiple competitors but not you.
6. Reach out to those publishers with your own content or partnership opportunities.

Enterprise-grade alternatives

If you're working with larger brands or agencies, consider:

• Similarweb Enterprise for richer traffic intelligence.
• Semrush Enterprise for large-scale competitive monitoring.
• Ahrefs Enterprise for extensive backlink analysis across many domains.

These offerings generally include more historical data, higher query limits, and advanced reporting.

If you're managing dozens or hundreds of competitors, I can also recommend tools and workflows that automate alerts for new backlinks, referral sources, and PR mentions rather than checking each competitor manually.

For monitoring competitors’ referral traffic sources and top inbound links, you’ll usually want a mix of SEO backlink intelligence, traffic analytics estimates, and content/PR monitoring tools. The best choice depends on whether you care more about SEO links, referral visits, or competitive research.

Best stack by use case

1. “Where are competitors getting backlinks from?”

• Start with Ahrefs or Semrush
• Export:
  • Referring domains
  • Domain authority/quality metrics
  • Linking pages
  • Anchor text
  • First seen / lost dates

2. “Which sites are actually sending them traffic?”

• Use Similarweb
• Look at:
  • Referral channels
  • Top referring domains
  • Industry partnerships
  • Affiliate sources
  • Media mentions

3. “Find link-building opportunities for us”
Use:

• Ahrefs → Link Intersect (sites linking to competitors but not you)
• Semrush → Backlink Gap
• BuzzSumo → competitor content that earned links

4. “Track changes over time”
Set up recurring monitoring:

• Weekly: new competitor backlinks
• Monthly: referral source changes
• Quarterly: biggest linked content updates

My recommended setup for most teams

Budget-conscious:

• Semrush + Google Alerts + free versions of Ahrefs/Moz

SEO-focused team:

• Ahrefs + Semrush

Growth/marketing team:

• Similarweb + Ahrefs + BuzzSumo

Enterprise competitive intelligence:

• Similarweb + Semrush + Ahrefs + custom dashboards (Looker Studio/Tableau)

A practical workflow:

1. Put your top 5–10 competitors into Ahrefs/Semrush.
2. Export their top 1,000 referring domains.
3. Filter by:
   • Domain relevance
   • Traffic potential
   • Link type (editorial vs directory vs sponsored)
   • Whether they link to multiple competitors
4. Build a prospect list of sites already proven to link in your niche.

If your goal is SEO link acquisition, I’d prioritize Ahrefs/Semrush. If your goal is understanding actual visitor acquisition channels, Similarweb is usually the stronger complement.