ChatGPT answers, unedited

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.

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.

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.

If your goal is to uncover where competitors get referral traffic and which websites send them the most links, no single tool does everything perfectly. The best approach is usually to combine one backlink intelligence platform with one traffic estimation platform.

Here's how the major tools compare:

1. Similarweb (best for referral traffic)

If your question is:

"Who is sending visitors to my competitors?"

Similarweb is usually the strongest option.

It shows estimated:

• Top referral websites
• Percentage of traffic from each referrer
• Outbound destinations
• Display ad partners
• Search vs social vs referrals
• Geographic traffic breakdown

Example:

competitor.com

Top Referrals

partner1.com        18%
directory.com       13%
reviewsite.com      8%
affiliate.com       5%

This is difficult to get accurately from backlink-only tools.

2. Ahrefs (best for inbound links)

Ahrefs excels at answering:

• Who links to competitors?
• Which pages attract the most links?
• Which links are new?
• Which links disappeared?
• Which domains link to competitors but not to you?

Useful reports include:

• Referring Domains
• Best by Links
• Link Intersect
• New Backlinks
• Lost Backlinks

One of the most valuable features is Link Intersect, which can reveal sites linking to several competitors but not your site—often strong outreach prospects.

3. Semrush (best all-around)

Semrush combines traffic estimates with SEO intelligence.

It includes:

• Traffic Analytics
• Referral sources
• Backlink Analytics
• Organic competitors
• Paid competitors
• Advertising research

If you want one subscription instead of multiple specialized tools, Semrush is often the most balanced choice.

4. Majestic (best for serious link builders)

Majestic focuses almost entirely on backlinks.

Strengths:

• Huge historical link database
• Trust Flow
• Citation Flow
• Link neighborhoods
• Link context

It's less useful for estimating traffic, but excellent for understanding a site's backlink profile.

Best workflow

A common competitive research workflow is:

1. Use Similarweb to identify top referral websites.
2. Use Ahrefs to inspect those referring domains and the specific links.
3. Use Ahrefs or Semrush's Link Intersect to find sites that link to competitors but not to you.
4. Prioritize outreach to high-authority domains that are sending both traffic and SEO value.

Can you monitor changes over time?

Yes, but with varying capabilities:

• Ahrefs: Alerts for new and lost backlinks.
• Semrush: Competitor backlink monitoring and changes.
• Similarweb: Tracks traffic trends and shifts in referral sources (depending on plan).
• Majestic: Historical backlink comparisons.

For enterprise-level competitive intelligence

If budget is less of a concern, these tools provide deeper market and referral insights:

• Similarweb Enterprise
• SparkToro (audience and website affinity)
• Demandbase One (B2B account intelligence)
• Crayon (competitive intelligence monitoring)

My recommendation by budget

• Best overall: Similarweb + Ahrefs
• Best single platform: Semrush
• Best for SEO agencies: Ahrefs
• Best for growth marketers focused on partnerships and referrals: Similarweb
• Best value: SE Ranking

If your specific goal is finding affiliate partners, directories, review sites, PR placements, and partnership opportunities that drive competitors' traffic, the combination of Similarweb (traffic sources) and Ahrefs (actual linking pages and domains) is generally the strongest.

If your goal is specifically to reverse-engineer where competitors get traffic and who links to them, no single tool does everything perfectly. The best approach is usually to combine one traffic intelligence platform with one backlink intelligence platform.

Here's how the major tools compare:

Best overall combination

1. Similarweb (best for referral traffic)

This is the strongest tool for answering questions like:

• Which websites send competitors traffic?
• What percentage comes from referrals?
• Which affiliates drive visits?
• Which partner sites are important?
• What channels are growing?

You'll see things like:

• Top referring websites
• Top destination sites
• Outgoing referral partners
• Traffic share by source
• Search vs social vs referral vs direct

Great for finding:

• affiliate programs
• review sites
• media partnerships
• marketplaces
• directories

2. Ahrefs (best backlink intelligence)

If your question is:

"Who links to my competitors?"

Ahrefs is arguably the industry leader.

Useful reports include:

• Best by links
• Referring domains
• New backlinks
• Lost backlinks
• Link intersect
• Broken backlinks

It also lets you filter by:

• DR
• traffic
• dofollow
• language
• first seen
• last seen

The Link Intersect report is especially useful:

Show me sites linking to Competitor A and B but not me.

That becomes an outreach list.

3. Semrush (best all-around)

Semrush combines:

• referral traffic estimates
• traffic journey
• backlinks
• authority score
• organic keywords
• paid search
• display advertising

If you only want one subscription, Semrush is probably the most balanced choice.

If referrals are your primary interest

Similarweb is noticeably stronger.

For example, you can discover:

Competitor →

Referral source →

Estimated traffic share

Which often reveals:

• affiliates
• publishers
• coupon sites
• comparison sites
• software marketplaces
• communities

If backlinks are your primary interest

I'd rank them:

1. Ahrefs
2. Majestic
3. Semrush
4. Moz

Majestic still has one of the largest historic link indexes.

Enterprise-level options

If budget isn't a concern:

• Similarweb Enterprise
• Semrush Enterprise
• Ahrefs Enterprise

These offer:

• API access
• historical snapshots
• traffic trends
• market share
• audience overlap
• bulk competitor tracking

My recommended stack by budget

<$100/month

• SE Ranking
• Similarweb free version

$200–400/month

• Ahrefs Standard
• Similarweb Starter

$500+/month

• Semrush Guru or Business
• Ahrefs
• Similarweb

This combination covers nearly every competitive intelligence need.

One limitation to keep in mind

No third-party SEO tool can see competitors' actual analytics. Referral traffic figures are modeled estimates based on panels, clickstream data, and other signals. Backlink databases, while very comprehensive, are also incomplete because the web is constantly changing. The most reliable strategy is to compare insights across tools rather than rely on a single source.

If you're trying to build a repeatable competitor-monitoring workflow, I can also recommend the best setup for automatically tracking:

• new backlinks earned by competitors,
• newly discovered referral partners,
• affiliate sites,
• PR mentions,
• and high-value link opportunities in a weekly dashboard.