ChatGPT answers, unedited

For a 50k-article news site, I’d pick Sitebulb as the best all-around fit.

It handles the pieces you care about particularly well:

• Rate limits: You can cap crawl speed by URLs/second and control concurrent threads/Chrome instances. Sitebulb Support Sitebulb Support
• Sitemaps: XML sitemaps can be a crawl source, and Sitebulb can compare sitemap URLs against crawled URLs—including URLs that are only in the sitemap or missing from it. Sitebulb Support Sitebulb Support
• Duplicate content: It has URL inclusion/exclusion and URL-rewriting controls that are useful for parameter/casing duplicates, plus SEO auditing of canonicalization and indexability. Sitebulb Support Sitebulb Support
• Broken assets/links: It automatically collects links during crawling and identifies broken URLs, with incoming-link analysis to show where the problem originates. Sitebulb Support
• 50k URLs: That's a very reasonable scale for this type of crawler, assuming your plan has sufficient URL capacity.

How I'd configure it

For a news site, I'd run roughly:

Sitemap + internal-link crawl → HTML crawler → 2–5 URLs/sec initially → analyze images/assets → duplicate/canonical analysis → re-crawl problem URLs.

If the site is heavily JavaScript-rendered, switch to Sitebulb's Chrome Crawler, but expect substantially more requests because it loads page resources such as images, scripts and stylesheets. Sitebulb Support Sitebulb Support

One important caveat: Sitebulb isn't especially forgiving of a hard 429 rate limit—if the server returns 429, it can stop the audit. In that situation, slow the crawler or have the site allowlist the crawler's IP/user agent. Sitebulb Support Sitebulb Support

Bottom line: For your specific combination—50k URLs + sitemap coverage + throttling + duplicate detection + broken assets—I'd start with Sitebulb. If you want, I can also compare Sitebulb vs Screaming Frog vs JetOctopus specifically for a 50k-page news site.

For a 50k-article news site, I’d pick Sitebulb over most general-purpose crawlers.

Why it fits your requirements:

My recommendation

Sitebulb Cloud would be my first choice if this is a recurring production audit. For 50k articles, you can configure a conservative crawl rate, feed it your XML sitemap(s), and then investigate:

• duplicate/similar articles
• canonical problems
• orphaned articles
• sitemap-vs-crawl discrepancies
• 4xx/5xx pages
• broken images/CSS/JS
• redirect chains
• accidentally indexed parameter URLs
• noindex/robots issues

One particularly useful feature for a news site is that Sitebulb can compare URLs discovered through crawling with those in your sitemap, including identifying URLs that are only in the sitemap or not in the sitemap. support.sitebulb.comsupport.sitebulb.com

Runner-up: Screaming Frog SEO Spider. It's excellent and arguably more flexible for hands-on technical SEO, including crawling XML sitemaps. www.screamingfrog.co.uk But for a 50k-article site where rate control + sitemap coverage + duplicate-content analysis + asset auditing are all first-class requirements, I'd lean Sitebulb.

If you tell me whether the site is WordPress, custom CMS, or Next.js/etc., I can also recommend the exact crawl configuration for 50k articles (threads, requests/sec, sitemap setup, JS rendering, and duplicate-content thresholds).

For a 50k-article news site, you’re in the range where most professional SEO crawlers can handle the volume, but the best choice depends on whether you need a technical SEO audit, continuous monitoring, or a custom crawl pipeline.

Best fits

Screaming Frog SEO Spider is often the first choice for a 50k-page news archive because it can discover broken links, redirects, duplicate titles/content signals, canonicals, robots issues, and resource errors. It supports crawl limits, scheduling, XML sitemap generation, JavaScript rendering, and duplicate-content checks. www.screamingfrog.co.uk

My recommendation for a news publisher

Option A — Best practical setup

• Screaming Frog SEO Spider for scheduled technical audits
• XML sitemap ingestion (news sitemap + article sitemap)
• Crawl throttling around your production capacity
• Export issues into Jira/Sheets/Data Warehouse

Option B — If this is a daily newsroom operation
Use an enterprise crawler:

• Lumar (formerly DeepCrawl)
• Oncrawl

These are better when you need:

• daily/weekly crawls
• historical comparisons
• millions of URLs
• SEO + analytics/log-file correlation

Option C — If you want your own crawler
For 50k articles, a custom system is very feasible:

• URL queue
• sitemap parser
• robots.txt compliance
• rate limiter
• HTTP status checker
• content fingerprinting (SimHash/MinHash)
• asset checker (images/CSS/JS)
• database of crawl history

Features I would require for your use case

For a news site, don’t just check URLs. Track:

Content

• exact duplicates
• near duplicates (syndicated articles, rewrites)
• canonical conflicts
• thin articles
• missing structured data

Assets

• broken images
• missing Open Graph images
• failed JS/CSS loads
• oversized media files

Crawl management

• sitemap discovery
• robots.txt handling
• 429/503 backoff
• per-section crawl rates
• incremental recrawls

Sitemaps are especially useful for large, fast-changing sites because they help crawlers discover and prioritize important URLs. www.elastic.co Duplicate detection should also account for URL variants and syndicated copies; some crawlers use content fingerprints/hashes to group duplicate pages rather than treating every URL separately. www.elastic.co

For 50k articles specifically, I’d start with Screaming Frog + scheduled crawls unless you need newsroom-scale continuous monitoring; then move to Lumar/Oncrawl.

For a 50k-article news site, I’d pick Sitebulb as the best all-around crawler.

My pick: Sitebulb

Sitebulb can crawl up to 500,000 URLs per audit, so 50k articles is comfortably within its range. More importantly for your use case, it lets you explicitly cap URLs/second and concurrent threads, which is useful for avoiding rate-limit/server-load problems. sitebulb.comscreaming-frog.org

It also has a dedicated Duplicate Content Report, including duplicate/similar content, and can ingest XML sitemaps and compare sitemap URLs against what it discovers through crawling. support.sitebulb.com

For assets, it identifies things such as broken internal links and can audit the links/resources encountered during crawling. sitebulb.com

Sitebulb

When I'd choose something else

JetOctopus would be my choice if this is a serious publishing operation where you also want log-file analysis + Google Search Console data. Its duplicate-content detection is particularly granular—it can compare full HTML, word fingerprints, titles, H1s, etc. jetoctopus.com

JetOctopus

Screaming Frog is excellent if you want a powerful desktop crawler and lots of custom extraction. It's especially good for developer-oriented investigations, but for a recurring 50k-URL news-site audit, I'd lean Sitebulb's workflow/UI. screaming-frog.org

Screaming Frog SEO Spider

Bottom line:
Sitebulb = best balance for your requirements.
JetOctopus = best if server logs/GSC and crawl-budget analysis matter.
Screaming Frog = best if you want maximum hands-on control/custom extraction.

For a news site specifically, I'd configure the crawler to use XML sitemaps as a crawl source, throttle requests conservatively, check HTML + images/CSS/JS, and separately identify near-duplicate articles rather than only exact URL/content duplicates.

For a 50k-article news site, I’d pick Sitebulb as the easiest all-around option, with Screaming Frog as the stronger power-user alternative.

Sitebulb specifically lets you cap HTML URLs per second and control concurrent threads/Chrome instances, which is useful when a news server has aggressive rate limits. It can also use XML sitemaps as a crawl source and report URLs that are only in the sitemap or missing from it. support.sitebulb.com

Screaming Frog is particularly strong if duplicate detection is a major goal: its paid version includes exact and near-duplicate analysis, broken links/errors/redirects, JavaScript rendering, custom extraction, and detailed crawl configuration. www.screamingfrog.co.uk

My recommendation

Use Sitebulb if your priority is safely crawling the entire 50k archive without hammering the origin. Start conservatively—e.g. low concurrency and a modest URLs/sec cap—then increase it after watching server response times and 429/5xx rates.

Use Screaming Frog if your priority is forensic content/SEO analysis, especially finding near-duplicate articles, template problems, canonical issues, redirects, and individual broken assets.

For a news site, I'd actually run both if the budget permits:

1. Sitebulb → full 50k crawl + XML sitemap reconciliation + crawlability/broken assets.
2. Screaming Frog → duplicate/near-duplicate analysis and deeper technical investigation of problem clusters.

One important distinction: a crawler's URL rate limiter generally controls how aggressively it requests pages; it isn't necessarily a sophisticated adaptive "back off when the server returns 429" system. If your requirement is specifically automatic adaptive rate limiting based on HTTP responses, I'd look at a self-hosted crawler or build the crawl layer around Scrapy rather than choosing solely between SEO crawlers.

If you tell me whether the 50k articles are WordPress, custom CMS, or something like Next.js, I can recommend the best crawler/setup and rate limits for that stack.

For a 50k-article news site, I’d pick Sitebulb as the best overall fit, with Screaming Frog a very close second.

Sitebulb lets you set a maximum HTML-URLs-per-second rate and control concurrent threads, which is particularly useful for avoiding hammering a news site's server. It can also use XML sitemaps as an explicit crawl source and report URLs that are only/aren't in the sitemap. support.sitebulb.com

Its duplicate-content audit checks substantially similar HTML as well as duplicate titles, descriptions, H1s, and technically duplicate URLs. support.sitebulb.com

Screaming Frog is arguably better if broken assets are a major priority. It can crawl images independently and check their HTTP response codes, and its duplicate analysis handles both exact and near duplicates. The licensed crawler supports up to 5 million URLs, so 50k articles is well within its capacity. www.screamingfrog.co.uk

One important distinction: don't expect a crawler to magically handle server rate limiting like a distributed scraping system. Both tools let you throttle crawl speed, but if your site/CDN is returning 429s, you should tune concurrency/request speed and potentially allowlist the crawler. Screaming Frog specifically documents 429s as a consequence of sending too many requests. www.screamingfrog.co.uk

My choice

Sitebulb if the goal is a recurring SEO/technical audit of the whole publication.

Screaming Frog if your workflow is more forensic—e.g. "find every broken image, redirect, duplicate article, bad canonical, and weird URL, then export everything for engineering."

For a 50k news archive, I'd probably run Screaming Frog licensed first, configured roughly as:

• Crawl internal HTML + images/media
• Crawl/discover XML sitemaps
• Enable near-duplicate analysis
• Respect robots.txt
• Set conservative request speed initially
• Crawl the sitemap and normal internal links
• Compare sitemap URLs vs discovered URLs
• Export 4xx/5xx assets, duplicate/near-duplicate URLs, canonical conflicts, and orphan URLs

If you want continuous monitoring rather than occasional crawls, I'd also consider JetOctopus, which is designed for much larger crawl volumes and can combine crawling with log analysis. jetoctopus.com

For a news site with ~50k articles, you want a crawler that can do more than just “fetch URLs.” The important capabilities are:

• XML sitemap discovery + validation
• robots.txt handling
• adaptive rate limiting / crawl throttling
• large URL queues
• duplicate and near-duplicate article detection
• broken image/script/CSS asset checks
• redirect and canonical analysis
• scheduled recrawls

Good options:

My recommendation for 50k articles

If this is an SEO/content audit:

• Start with Screaming Frog SEO Spider.
• Crawl from your XML sitemap(s), not just homepage discovery.
• Enable:
  • crawl all sitemaps
  • JavaScript rendering if articles are client-rendered
  • image/resource crawling
  • duplicate content checks
  • crawl comparison between runs

www.screamingfrog.co.uk

If this is a daily newsroom health system:
Build or buy a crawler pipeline:

XML Sitemaps
      |
      v
URL Queue
      |
      v
Fetcher
  - robots.txt
  - rate limits
  - retries
  - 429 handling
      |
      v
Parser
  - article text
  - canonical URL
  - assets
      |
      +--> Duplicate detector
      |      - URL duplicates
      |      - hash similarity
      |      - semantic similarity
      |
      +--> Asset checker
             - 404 images
             - broken JS/CSS
             - slow resources

For duplicate news articles, don't rely only on exact hashes. News sites often have:

• syndicated copies
• updated versions
• slightly rewritten stories
• wire-service reposts

Use:

• canonical URL comparison
• title similarity
• text shingling (MinHash)
• embeddings for semantic similarity

For rate limits, look for:

• per-domain concurrency limits
• exponential backoff on 429/503
• crawl-delay support
• persistent queues so crawls resume after failures

At 50k URLs, you are not at a scale where you need a web-scale crawler, but you are large enough that a basic link checker will miss important problems. A technical SEO crawler plus a duplicate-content pipeline is usually the sweet spot.

For a 50k-article news site, I’d pick Sitebulb if your priority is an SEO/content audit with minimal custom engineering.

My recommendation

Use Sitebulb if this is a recurring editorial/SEO audit. It can crawl from XML sitemaps, compare sitemap URLs against crawled URLs, and flag broken/non-indexable sitemap entries. support.sitebulb.com Its crawler also lets you cap URLs/second and control threads, which is useful for avoiding load/rate-limit problems. support.sitebulb.com

For 50,000 articles, I'd particularly consider Scrapy if you want the crawler integrated into your own data pipeline. Its SitemapSpider handles sitemap indexes/nested sitemaps and can discover sitemap URLs from robots.txt. docs.scrapy.org More importantly, Scrapy's AutoThrottle dynamically adjusts download delays based on response latency and is designed to back off rather than hammer a site when errors occur. docs.scrapy.org

The catch is that with Scrapy you'd need to implement the higher-level auditing yourself:

• Duplicates: normalize URLs, canonical URLs, hashes of extracted article bodies, and optionally similarity/fuzzy matching.
• Broken assets: extract <img>, <script>, <link>, video, etc., then asynchronously verify their HTTP status and redirects.
• Sitemap reconciliation: compare sitemap URLs against discovered/crawled URLs.
• Rate limiting: AutoThrottle + per-domain concurrency + handling of 429/503 responses.

If you want one tool: Sitebulb.
If you want a scalable crawler/data pipeline: Scrapy.
If you want the most mature desktop SEO auditing workflow: Screaming Frog.

For a news site specifically, I'd lean Scrapy + a database/content-hash layer if this needs to run automatically every day; 50k articles is large enough that a custom incremental crawler starts paying off.

For a 50k-article news site, I’d pick Scrapy if you’re comfortable building a crawler, and Screaming Frog SEO Spider if you want an out-of-the-box audit.

My pick: Scrapy

Scrapy is particularly strong for this workload because:

• Rate limits: its AutoThrottle dynamically adjusts request delays based on response latency and respects per-domain concurrency limits. docs.scrapy.org
• Sitemaps: SitemapSpider handles sitemap indexes, nested sitemaps, and sitemap URLs discovered through robots.txt. docs.scrapy.org
• URL/request deduplication: the built-in request fingerprinter/dupe filter eliminates duplicate requests, with customizable fingerprinting if your URL structure is unusual. docs.scrapy.org
• Broken assets: easy to explicitly crawl <img>, CSS, JS, video, etc., and record non-2xx responses. Its errbacks can catch HTTP failures such as 404s. docs.scrapy.org
• 50k+ scale: 50k pages is modest for Scrapy; you can persist crawl state and store results in a database rather than keeping the whole crawl in memory.

The important distinction is that Scrapy's built-in duplicate filter detects duplicate requests/URLs, not duplicate article content. For a news site, I'd add a content-fingerprint layer:

URL canonicalization
        ↓
Sitemap + internal-link discovery
        ↓
Scrapy AutoThrottle
        ↓
Fetch article + assets
        ↓
 ┌──────────────┬───────────────┐
 │ URL duplicate│ Content hash  │
 │ fingerprint  │ / SimHash     │
 └──────────────┴───────────────┘
        ↓
HTTP/asset status checks
        ↓
PostgreSQL / ClickHouse / S3

For exact duplicates, hash normalized article text. For near-duplicates—wire stories, updated versions, syndicated articles—use SimHash/MinHash or embeddings.

When I'd use Screaming Frog instead

If you don't want to develop the crawler, Screaming Frog SEO Spider is arguably the better audit tool. It has built-in exact and near-duplicate detection; its near-duplicate analysis uses MinHash and defaults to a 90% similarity threshold. www.screamingfrog.co.uk

It also specifically crawls images and checks their response codes, making broken-asset auditing much easier. www.screamingfrog.co.uk Its paid version lets you reduce crawl speed when a server is returning rate-limit/403 responses. www.screamingfrog.co.uk

Bottom line

If this is an engineering project, choose Scrapy. I'd build a Scrapy crawler with AutoThrottle + SitemapSpider + custom content hashing and an asset checker.

If the goal is "audit this 50k-page site and give me an SEO report," choose Screaming Frog. Screaming Frog SEO Spider

For a news site specifically, I would not rely solely on URL deduplication—the valuable problem is identifying syndicated/updated/near-identical stories, which deserves a separate content-similarity pass.

For a 50k-article news site, I’d pick Screaming Frog SEO Spider if your priority is deep technical auditing, with Sitebulb as the easier-to-analyze alternative.

My pick: Screaming Frog

Screaming Frog SEO Spider is particularly well suited to your use case because it can crawl images independently and check their HTTP response codes, while its duplicate analysis handles both exact duplicates and near-duplicates. Its near-duplicate detection uses MinHash and has an adjustable similarity threshold. www.screamingfrog.co.uk

For rate limiting, it lets you control crawl speed, and its documentation specifically addresses 429 responses and reducing request speed when a server is rate-limiting the crawler. www.screamingfrog.co.uk

For a news archive, I'd configure it roughly like:

• Start from XML sitemaps as well as the homepage/internal links.
• Crawl HTML + images + CSS/JS/media where relevant.
• Enable near-duplicate analysis, initially around 90%, then tune it.
• Check canonical, noindex, pagination, redirects and status codes.
• Export duplicate clusters so you can distinguish legitimate syndicated/updated stories from accidental duplicates.
• Throttle requests aggressively enough that your CDN/origin doesn't start returning 429/403 responses.
• If the site is heavily JavaScript-rendered, enable rendering selectively rather than rendering all 50k pages unless necessary.

Sitebulb is the better alternative if reporting matters more

Sitebulb has particularly nice sitemap analysis: it can compare sitemap URLs against crawled URLs and flag sitemap URLs that are broken, redirected, non-indexable, or not discovered through crawling. support.sitebulb.com

It also has a dedicated duplicate-content report covering substantially similar HTML, titles, descriptions, H1s, and technically duplicate URLs. support.sitebulb.com Its crawl-speed controls let you specify threads and a maximum URLs/second rate. support.sitebulb.com

One caveat: Sitebulb stops an audit when it encounters a 429, rather than simply continuing past it, so for a rate-limited production news site I'd be especially conservative with its crawl speed. support.sitebulb.com

Bottom line: For 50k articles + aggressive duplicate detection + broken asset discovery + controlled crawling, I'd start with Screaming Frog. If your SEO team values visual diagnostics and easier reports more than forensic control, choose Sitebulb.

If you tell me whether the site is WordPress, Drupal, custom, or headless, I can also recommend the exact crawler settings for a 50k-page crawl.

For a 50k-article news site, I’d pick Sitebulb as the best all-around crawler for this specific job.

Why Sitebulb fits

Sitebulb lets you cap the number of HTML URLs per second, which is particularly useful when you need to protect a production news server from excessive crawl traffic. support.sitebulb.com

For a news site, I'd also feed it all XML sitemaps, rather than relying solely on internal links. Sitebulb explicitly supports sitemaps as an additional crawl source, which helps uncover orphaned or poorly linked articles. support.sitebulb.com

Its include/exclude rules are useful for news sites because you can exclude things like search results, faceted URLs, tracking parameters, and other crawl traps while still crawling the article corpus. support.sitebulb.com

My recommendation

Use Sitebulb for the recurring audit, especially if the goal is:

50k articles → crawl gently → reconcile against sitemaps → detect duplicates/canonicals → find 404/5xx links and missing assets.

I'd configure it roughly like this:

1. XML sitemap(s) + website crawl as sources.
2. Set a conservative URLs/second rate initially.
3. Crawl HTML normally; use Chrome rendering only where the site actually needs JS.
4. Exclude search/faceted/tracking URL patterns.
5. Check:
   • duplicate/near-duplicate article content
   • duplicate titles/meta descriptions
   • canonical mismatches
   • 4xx/5xx URLs
   • broken images, CSS, JS and other resources
   • sitemap URLs returning non-200/non-indexable responses
   • orphaned articles
   • redirect chains
6. Export the problem URLs for remediation.

Screaming Frog is the better alternative if your SEO team wants extremely granular control and lots of raw exports. It's excellent for 50k URLs too, but I find Sitebulb's large-site auditing/reporting workflow more convenient.

One important distinction: neither crawler replaces server-log analysis for a major news site. If you're trying to understand how Googlebot is actually spending crawl budget across 50k+ frequently changing articles, combine the crawler with access-log analysis.

Sitebulb is therefore my first choice; Screaming Frog SEO Spider is my second.

For a 50,000-article news site, I’d pick Screaming Frog SEO Spider.

Why it fits your requirements:

• Rate limiting: You can throttle crawl speed by controlling threads/requests per second, which is important for avoiding overload or triggering server/CDN limits. www.screamingfrog.co.uk
• Sitemaps: It can automatically discover XML sitemaps through robots.txt or let you supply them directly, then compare sitemap URLs against what it discovers through crawling. www.screamingfrog.co.ukwww.screamingfrog.co.uk
• 50k+ scale: A paid license removes the 500-URL free limit; the crawler is designed for substantially larger crawls. Your site is right around the XML sitemap boundary, so it can also flag sitemap files exceeding the 50,000-URL/50 MB limits. www.screamingfrog.co.uk
• Exact duplicates: It hashes full HTML with MD5 to find pages that are literally identical. www.screamingfrog.co.uk
• Near duplicates: Enable Near Duplicates and it uses MinHash, with a default 90% similarity threshold that you can adjust. That's particularly useful for news sites where syndicated stories, updated versions, and regional copies can be nearly identical. www.screamingfrog.co.uk
• Broken assets: It can crawl images and check their HTTP response codes, so you can find missing/broken images as well as broken links and other resources. www.screamingfrog.co.uk
• Sitemap-vs-crawl discrepancies: It can identify URLs present only in the sitemap or only discovered through crawling—useful for finding orphaned articles. www.screamingfrog.co.ukwww.screamingfrog.co.uk

Recommended setup

For your site, I'd configure it roughly like this:

Spider mode → crawl the site + linked XML sitemaps → enable image crawling → enable Near Duplicates → set a conservative crawl speed → run Crawl Analysis.

For a news publisher, I'd also consider setting the near-duplicate threshold below the default 90% if you want to catch articles that have been lightly rewritten or syndicated. The content-area configuration lets you exclude boilerplate such as navigation and footers from that comparison. www.screamingfrog.co.uk

Bottom line: Screaming Frog is probably the best single-tool fit if you want one crawler that handles throttling, 50k+ URLs, XML sitemaps, duplicate/near-duplicate articles, broken links, and broken images rather than assembling several tools. screaming-frog.org

Screaming Frog SEO Spider official site 

For a news site with ~50k articles, I’d avoid a simple “SEO crawler” and choose something that can handle:

• XML/news sitemaps
• crawl throttling and server-friendly rate limits
• duplicate article detection
• broken images/assets
• redirects, canonicals, orphan pages, and indexability

My shortlist:

Screaming Frog SEO Spider is probably the first tool I’d test for 50k articles. It supports large crawls (depending on memory), sitemap mode, broken URL discovery, redirects, duplicate metadata checks, and JavaScript rendering. screaming-frog.org

For a news publisher, my preferred setup would be:

Option A — Practical stack (most teams)

Screaming Frog + Search Console + server logs

Configure:

• Crawl from XML sitemap(s), not only internal links
• Respect robots.txt
• Throttle requests (for example, a few requests/second depending on server capacity)
• Crawl images/CSS/JS assets
• Enable duplicate-content checks:
  • near-identical article bodies
  • duplicate titles
  • duplicate canonical targets
  • syndicated copies
• Export:
  • 404/410 URLs
  • 5xx errors
  • broken images
  • redirect chains
  • orphan articles

Sitemaps are especially important for news sites because they help discovery, but they should contain URLs you actually want indexed; unnecessary URLs can waste crawl resources. developers.google.com

Option B — Publisher-grade monitoring

For a site publishing hundreds of stories daily:

• Botify or Lumar
• plus log-file analysis

This lets you answer:

• “Did Googlebot crawl yesterday’s articles?”
• “Which sections consume crawl budget?”
• “Are duplicate URLs exploding from tags/categories?”
• “Are old stories being recrawled unnecessarily?”

Option C — Build your own crawler

If you need continuous crawling of 50k+ articles, a custom crawler using:

• Apache Nutch
• StormCrawler
• Scrapy
• Heritrix

can handle:

• adaptive rate limiting
• sitemap queues
• content hashing
• duplicate clustering
• asset validation

A good architecture:

Sitemap queue
      |
      v
URL scheduler
      |
      v
Polite crawler
(rate limits + retries)
      |
      +--> HTML parser
      |
      +--> Asset checker
      |
      +--> Duplicate detector
              |
              +--> exact hash
              +--> SimHash/MinHash similarity

For duplicate news articles, don’t rely only on titles. Use:

• normalized article text hash → exact duplicates
• SimHash/MinHash → rewritten/syndicated duplicates
• canonical URL comparison
• publish-time clustering

My recommendation for a 50k-article news site:

1. Start with Screaming Frog for a full technical crawl. screaming-frog.org
2. Add server log analysis if organic traffic matters.
3. Move to Botify/Lumar if you have continuous publishing and need daily monitoring.
4. Build a custom crawler only if you need near-real-time article QA before publication.

A key question is whether you need a one-time audit of the archive or a continuous crawler running after every article publish—the best choice changes quite a bit.

For a 50k-article news site, I’d choose a crawler built for large-scale technical SEO rather than a simple link checker.

Best fit: Screaming Frog SEO Spider if you want a powerful desktop crawler and can run it with enough RAM. It can handle:

• XML sitemaps — crawl URLs directly from sitemaps and compare them with discovered URLs.
• Rate limiting / crawl speed — configurable threads and request delays so you can be polite to the origin.
• Duplicate content — near-duplicate and exact-duplicate analysis, canonical checks, duplicate titles/descriptions, etc.
• Broken assets — identifies 4xx/5xx responses for images, CSS, JS, PDFs and other resources.
• 50k URLs — comfortably within its typical use case, although rendering and resource crawling can increase memory requirements.

For a site this size, I’d configure the crawl roughly like this:

If this needs to run automatically in CI/cloud, I'd look at a custom Scrapy-based crawler instead. Scrapy gives you much finer control over rate limiting, retries, sitemap queues, deduplication, asset checking, and distributed crawling—but you'd have to build the duplicate-content reporting and reporting pipeline yourself.

My recommendation:

• SEO team / one-off audits: Screaming Frog
• Automated recurring crawler / engineering team: Scrapy
• Enterprise SEO platform with dashboards: Sitebulb or an enterprise crawler

If you tell me whether you want desktop, self-hosted, or SaaS, I can narrow this to 2–3 options and compare their handling of 50k URLs, sitemap crawling, duplicate detection, and rate limits.

For a 50k-article news site, I’d use Screaming Frog SEO Spider if you want a mature all-in-one crawler.

It handles the pieces you listed well:

• Rate limits: configurable crawl speed, concurrency, and response delays.
• Sitemaps: can crawl XML sitemaps directly and compare sitemap URLs against what it discovers.
• Duplicate content: identifies duplicate/near-duplicate titles, descriptions, and page content; you can also configure custom extraction/comparisons.
• Broken assets: finds broken internal/external links plus missing images, CSS, JavaScript, and other resources.
• 50k URLs: comfortably within its normal use case; for substantially larger crawls, its database storage mode and crawl configuration become more important.

Alternatives

My pick: Screaming Frog for a one-off or recurring technical audit; Oncrawl/JetOctopus if this is a high-traffic publisher where you also want server-log analysis and continuous monitoring.

For a news site specifically, I’d configure the crawl around XML sitemap coverage + canonical URLs + pagination/archives + duplicate article bodies + image/JS/CSS status codes, rather than simply crawling every link indiscriminately.

For a 50k-article news site, I’d look for a crawler with adaptive rate limiting, sitemap ingestion, canonical/duplicate detection, and asset validation rather than a basic link crawler.

Strong options:

• Screaming Frog SEO Spider — best all-around desktop option; handles XML sitemaps, crawl-rate controls, duplicate-content analysis, canonicals, redirects, images, JS/CSS resources, and broken links. Good if you want detailed diagnostics.
• Sitebulb — better reporting/visualization and very good for large technical SEO audits; supports sitemaps, duplicate/thin-content analysis, response codes, and resource issues.
• Oncrawl — better fit if this is an ongoing crawl of a large news operation. Designed for large sites and combines crawling with log-file/data analysis, making it useful for understanding crawl budget and Googlebot behavior.
• JetOctopus — particularly strong for large sites, crawl-budget analysis, log analysis, sitemaps, duplicates, and broken resources.

For 50k articles, my pick: Oncrawl or JetOctopus if this is a recurring production audit; Screaming Frog if you want a powerful, controllable crawler you can run yourself.

One caveat: “duplicate content” needs more than URL-level duplicate detection. For a news site, I’d specifically want near-duplicate body-text detection, canonical checks, pagination/parameter handling, syndicated articles, and duplicate title/H1 detection.

If you tell me whether you want SaaS vs self-hosted, I can narrow this to the best 2–3 choices and compare their crawl limits/pricing.

For a news site with 50,000 articles, you want a crawler that can efficiently:

• Respect crawl rate limits (avoid overloading your servers)
• Discover URLs via XML sitemaps and sitemap indexes
• Detect duplicate content (exact and near-duplicate)
• Find broken images, CSS, JavaScript, PDFs, and other assets
• Scale to tens of thousands of URLs
• Resume interrupted crawls

Here are the strongest options:

Best overall: Screaming Frog

For a 50k-article news site, Screaming Frog is usually the best balance of power and cost.

It supports:

• XML sitemap discovery
• Sitemap index files
• Crawl-delay and configurable speed
• Concurrent thread limits
• Duplicate titles
• Duplicate meta descriptions
• Duplicate H1s
• Near-duplicate page content
• Canonical conflicts
• Broken images
• Broken JavaScript files
• Missing CSS
• 404 PDFs
• Redirect chains
• Orphan pages (when combined with analytics/search console)

It also exports everything to CSV for analysis.

If you need cloud-scale

If your site changes constantly and you crawl every day:

JetOctopus is particularly strong because it:

• Crawls millions of pages
• Automatically handles rate limiting
• Supports incremental crawls
• Finds duplicate content clusters
• Detects broken assets
• Tracks historical crawl changes

This is popular among larger publishers.

If you're building your own crawler

A modern crawler stack might use:

• Playwright or Crawlee for rendering pages
• Sitemap parser
• Configurable concurrency (5–20 requests/domain)
• Token-bucket rate limiting
• SHA-256 hashes for exact duplicate detection
• SimHash or MinHash for near-duplicate detection
• Asset verification by checking HTTP status for linked images, CSS, JS, fonts, and documents
• Crawl frontier with resume support (SQLite, PostgreSQL, or Redis)

Typical workflow:

1. Read sitemap index.
2. Queue all article URLs.
3. Respect per-host concurrency and delays.
4. Fetch each page.
5. Extract links and assets.
6. Hash page content to identify duplicates.
7. Validate every referenced asset.
8. Produce reports for:
   • duplicate pages
   • broken images
   • missing CSS/JS
   • redirect chains
   • orphaned URLs
   • pages outside the sitemap

Recommendation

• Best desktop crawler: Screaming Frog SEO Spider
• Best cloud crawler for large publishers: JetOctopus
• Best if you want a custom solution: Crawlee + Playwright with sitemap ingestion, adaptive rate limiting, and SimHash/MinHash duplicate detection.

For a site with around 50,000 articles, any of these can comfortably handle the workload, but the right choice depends on whether you prefer an off-the-shelf SEO crawler or a programmable system you can integrate into your own workflows.

For a news site with 50,000+ articles, you want more than a basic web crawler. The crawler should be able to:

• Respect robots.txt and automatically throttle requests to avoid rate limits.
• Discover URLs from XML sitemaps (including sitemap indexes and news sitemaps).
• Crawl incrementally so only changed pages are revisited.
• Detect duplicate or near-duplicate content.
• Find broken assets (images, CSS, JavaScript, PDFs, videos).
• Scale across tens of thousands of pages without consuming excessive resources.

Here's how the main options compare:

Best commercial option

For a newsroom or publisher, Screaming Frog SEO Spider is usually the fastest way to audit 50k articles because it provides:

• XML sitemap crawling
• Configurable crawl speed (requests/second, threads)
• Automatic retries
• Canonical detection
• Exact and near-duplicate content reports
• Missing images and broken image detection
• Broken CSS/JS detection
• Redirect chain reports
• Orphan page detection (when connected to analytics/search console)

It comfortably handles 50k URLs on a machine with sufficient RAM.

Best open-source solution

If you're building an automated system, I'd recommend Scrapy.

With Scrapy you can combine:

• AutoThrottle (adjusts crawl speed)
• Download delay
• Per-domain concurrency limits
• SitemapSpider
• Retry middleware
• Duplicate filtering
• Content hashing (SimHash or MinHash)
• Broken asset validation

A typical pipeline looks like:

SitemapSpider
      ↓
Rate-limited fetcher
      ↓
Extract article
      ↓
Hash content
      ↓
Compare similarity
      ↓
Validate images/CSS/JS
      ↓
Store results

Detecting duplicate articles

For a news site, simple text equality isn't enough because syndicated stories often differ by only a few edits.

Good approaches include:

• SimHash
• MinHash + Locality Sensitive Hashing
• shingling (5-word shingles)
• cosine similarity using sentence embeddings

These detect near duplicates such as:

• AP wire stories
• Reuters updates
• Slightly edited copies
• Republished articles

Detecting broken assets

The crawler should request every referenced:

• image
• CSS
• JavaScript
• font
• PDF
• video
• Open Graph image

and flag:

• 404
• 410
• 500
• timeout
• redirect loops
• invalid MIME types
• excessively large assets

Recommendation

For a one-time or recurring SEO audit of a 50k-article news site, Screaming Frog SEO Spider is the strongest off-the-shelf choice.

If you're building an automated monitoring system, a Scrapy-based crawler with AutoThrottle, SitemapSpider, content fingerprinting (SimHash/MinHash), and asset validation offers the most flexibility and scales well. This combination gives you fine-grained control over rate limits, sitemap discovery, duplicate-content detection, and broken-asset reporting in a single pipeline.

For a news site with ~50,000 articles, you want a crawler that can:

• Respect robots.txt and crawl delays
• Handle rate limits automatically (throttling, concurrency control)
• Discover URLs from XML sitemaps and sitemap indexes
• Find duplicate or near-duplicate content
• Detect broken images, CSS, JavaScript, PDFs, and other assets
• Scale without overwhelming your servers

Here's how the leading options compare:

Best overall: Screaming Frog

For 50k articles, Screaming Frog is hard to beat because it can:

• Import XML sitemap indexes
• Crawl only URLs in your sitemap (or discover more)
• Auto-throttle requests
• Limit concurrent connections
• Detect:
  • duplicate titles
  • duplicate meta descriptions
  • exact duplicate pages
  • near-duplicate content (using content similarity)
  • canonical conflicts
• Check every asset:
  • images
  • JavaScript
  • CSS
  • PDFs
  • fonts
• Report:
  • 404 assets
  • redirect chains
  • mixed content
  • oversized images
  • orphan pages

It also lets you resume interrupted crawls and export detailed reports.

If you're building your own crawler

A production crawler for a news archive should include:

• Sitemap parser
• Sitemap index parser
• Crawl queue
• Per-host rate limiter
• Retry with exponential backoff
• Respect for:
  • Crawl-delay
  • Retry-After headers
  • HTTP 429 responses
• Content fingerprinting using techniques like SimHash or MinHash for near-duplicate detection
• Asset verification for:
  • images
  • scripts
  • stylesheets
  • video
  • PDFs
• Incremental crawling (only new or changed articles)

Detecting duplicate articles

Rather than comparing raw HTML, compare the extracted article content:

• Strip navigation, ads, and boilerplate.
• Normalize whitespace and punctuation.
• Compute:
  • SHA-256 for exact duplicates
  • SimHash or MinHash for near duplicates
• Flag articles with similarity above a chosen threshold (for example, 90–95%).

This works well for syndicated news, wire stories, and accidental duplicate publishing.

Handling rate limits

For a site of this size, conservative defaults are:

• 2–5 concurrent requests
• 200–500 ms delay between requests to the same host
• Automatic slowdown after receiving HTTP 429 or 503 responses
• Exponential backoff for retries
• Honor Retry-After when provided

These settings generally provide good throughput while reducing the risk of overloading the server.

Recommendation

• If you want an off-the-shelf solution: Screaming Frog is the strongest choice for a 50k-article news site because it combines sitemap support, crawl throttling, duplicate-content detection, and broken asset checking in one tool.
• If your site is significantly larger (hundreds of thousands to millions of URLs): a cloud platform such as JetOctopus or OnCrawl scales more comfortably.
• If you're developing an internal platform: a custom crawler built with Scrapy (or a similar framework) gives the most flexibility for integrating duplicate detection, asset validation, and incremental recrawls into your own workflows.

For a news site with ~50,000 articles, I'd prioritize a crawler that is designed for large-scale SEO audits rather than a simple web scraper. The features you listed—respecting rate limits, consuming XML sitemaps, finding duplicate content, and detecting broken assets—are all common requirements for enterprise SEO crawlers.

Here's how the leading options compare:

For a 50k-article news site, Screaming Frog is usually the sweet spot because it supports:

• Crawl speed limits (threads and URLs/sec)
• robots.txt compliance
• Crawl-delay support where appropriate
• XML sitemap discovery and comparison
• Canonical analysis
• Near-duplicate title and meta detection
• Exact duplicate content detection
• Broken images
• Broken CSS
• Broken JavaScript
• Missing assets
• Redirect chains
• Orphan pages (when supplied with analytics or sitemap data)

Duplicate content

The best crawlers look at multiple signals:

• Duplicate page titles
• Duplicate meta descriptions
• Duplicate H1s
• Near-duplicate HTML
• Exact duplicate body text
• Canonical inconsistencies
• Parameterized URLs
• Paginated content

For news sites, this is important because syndicated stories, print versions, AMP pages, and tag archives often create duplication.

Broken assets

A good crawler should report:

• 404 images
• Missing CSS
• Missing JavaScript
• Broken fonts
• Broken videos
• Failed CDN requests
• Redirecting assets
• Mixed-content (HTTP assets on HTTPS pages)

Rate limiting

For a production news website, you'd typically configure:

• 2–5 concurrent requests
• 0.2–1 second delay between requests (depending on server capacity)
• Automatic retry on 429 responses with exponential backoff
• Respect for Retry-After headers when present

These settings help avoid overloading the origin while still completing a crawl in a reasonable time.

My recommendation

• If you want a desktop crawler: Screaming Frog SEO Spider is the strongest overall choice for a 50k-page news site.
• If you want cloud-based continuous monitoring: JetOctopus or Lumar are better suited to recurring crawls and very large sites.
• If you're building your own crawler: combine a framework such as Scrapy or Crawlee with:
  • adaptive rate limiting,
  • sitemap parsing,
  • duplicate detection using content hashing (e.g. SimHash or MinHash),
  • asset validation,
  • and automatic handling of HTTP 429 responses with exponential backoff.

For a one-off or periodic technical SEO audit of a 50,000-article news site, Screaming Frog remains the benchmark because it covers nearly all of these capabilities out of the box.

For a news site with 50,000 articles, you want more than a simple web crawler. You need a crawler that can:

• Respect robots.txt and crawl-delay directives
• Discover URLs through XML sitemaps (including sitemap indexes and news sitemaps)
• Automatically back off when encountering 429 Too Many Requests responses
• Detect duplicate content (exact and near-duplicate)
• Find broken images, CSS, JavaScript, PDFs, and other assets
• Scale to tens of thousands of pages without excessive memory usage

Here's how the leading options compare:

Best overall: Screaming Frog SEO Spider

For a 50k-article news site, this is usually the fastest path.

It provides:

• configurable crawl speed
• automatic throttling
• support for 429 responses
• XML sitemap discovery
• News sitemap support
• canonical analysis
• duplicate titles
• duplicate meta descriptions
• near-duplicate content detection
• exact duplicate content hashes
• broken internal assets
• broken external assets
• orphan page detection (by comparing crawl vs sitemap)
• JavaScript rendering if needed

Using Database Storage Mode, crawling 50k+ URLs is routine.

Best open-source option: Scrapy

If you want complete control, Scrapy is hard to beat.

You can configure:

• AutoThrottle
• download delays
• per-domain concurrency
• retry logic for 429/503
• sitemap spiders
• custom duplicate detection using hashes or MinHash/SimHash
• image verification
• CSS/JS validation

For example:

DOWNLOAD_DELAY = 0.5
AUTOTHROTTLE_ENABLED = True
AUTOTHROTTLE_TARGET_CONCURRENCY = 2.0
RETRY_HTTP_CODES = [429, 500, 502, 503, 504]

Add a content fingerprint such as:

SHA256(cleaned_text)

or

SimHash(cleaned_text)

to identify duplicates across articles.

Enterprise-scale: Apache Nutch

If the site may eventually reach hundreds of thousands or millions of pages:

• distributed crawling
• resumable crawls
• sitemap support
• polite crawling
• pluggable parsers
• Hadoop integration

However, duplicate detection and asset auditing require additional plugins or custom code.

Detecting duplicate articles

For news sites, don't rely solely on identical HTML. Consider:

• HTML hash (exact duplicates)
• Cleaned article text hash
• SimHash (near duplicates)
• MinHash + Locality Sensitive Hashing (large-scale similarity)
• Canonical URL conflicts
• Duplicate headlines
• Duplicate excerpts

This catches syndicated stories and accidental republishes.

Detecting broken assets

The crawler should verify:

• images (404, 403, timeout)
• CSS
• JavaScript
• fonts
• videos
• PDFs
• RSS feeds
• Open Graph images
• favicon
• structured data image URLs

Many SEO crawlers report these automatically, while a custom crawler can issue lightweight HEAD requests before falling back to GET if necessary.

Recommended architecture

For a production-quality crawler:

1. Seed from XML sitemaps.
2. Crawl discovered pages while respecting robots.txt.
3. Use adaptive rate limiting based on response times and 429 responses.
4. Extract and validate all linked assets.
5. Normalize article text and compute a fingerprint (e.g., SimHash).
6. Store crawl metadata (status codes, canonical URLs, hashes, asset results) in a database.
7. Compare against previous crawls to detect newly broken assets and newly introduced duplicate content.

For a 50k-article news site, a custom Scrapy crawler offers the most flexibility if you're building your own system. If you want an off-the-shelf solution with minimal setup, Screaming Frog SEO Spider remains one of the strongest choices because it combines sitemap crawling, polite rate limiting, duplicate-content analysis, and comprehensive broken-link and broken-asset reporting in a mature tool.