Desktop site crawler

AI Crawler Check vs Screaming Frog SEO Spider

Screaming Frog is the better tool for crawling a whole site and finding every URL your robots.txt blocks for one chosen user-agent. AI Crawler Check is the better tool for testing one URL against 265 crawlers at once, with nothing to install. Technical SEOs usually want both.

Competitor facts verified 2026-10-18 Source: screamingfrog.co.uk pricing and robots.txt tutorial

Short answer

Use Screaming Frog when the question is "which of my URLs does this crawler lose?" and you are happy to install desktop software. Use AI Crawler Check when the question is "which crawlers lose this site?" and you want the answer in a browser in about a minute, for free.

Choose Screaming Frog SEO Spider when

You need to crawl every URL on a large site and list exactly which ones robots.txt blocks, with the matching line for each.
You want to edit a draft robots.txt and see the effect on a real crawl before it goes live, using the custom robots.txt feature.
You need JavaScript rendering, structured data validation, broken links and hreflang checks in the same crawl.
You already own a licence and work in the tool every day.
You need to test a site that is not publicly reachable, such as a staging server behind your VPN.

Choose AI Crawler Check when

You want to know how 265 different crawlers treat your site in one pass, not one user-agent per crawl.
You cannot or do not want to install desktop software, for example on a locked-down work laptop or a phone.
You want AI-specific context: which bots train models, which fetch pages for live answers and which are user-triggered assistants.
You want the wider GEO picture as well: llms.txt, schema and the rest of the 42 checks in one report.
You need a shareable result for a client who will never open an SEO crawler.

Side by side

AI Crawler Check compared with Screaming Frog SEO Spider
What you are comparing	AI Crawler Check	Screaming Frog SEO Spider
Comparable. What it crawls	One URL per check, tested against every crawler we track	Every URL it can discover on the site, as one user-agent at a time
Advantage AI Crawler Check. Number of user-agents per run	265, sorted into 8 categories	One, chosen in the configuration
Advantage Screaming Frog SEO Spider. Finds every blocked URL on a large site	No. It tests the URLs you give it, up to 20 per batch	Yes. Blocked by robots.txt filter with the matched line for each URL
Advantage Screaming Frog SEO Spider. Test a draft robots.txt before publishing	Use our robots.txt generator and checker separately	Yes, custom robots.txt with a licence, applied to a real crawl
Advantage AI Crawler Check. Install required	None. Runs in any browser	Desktop application for Windows, macOS or Linux
Advantage AI Crawler Check. Price	Free, no sign-up	Free up to 500 URLs; a licence is $279 per user per year for 1 to 4 licences (read 2026-10-18)
Advantage Screaming Frog SEO Spider. Wider technical SEO audit	42 GEO checks, focused on AI readiness	Very broad: links, redirects, metadata, hreflang, rendering, structured data, accessibility and more
Advantage AI Crawler Check. AI crawler purpose and tier	Each bot labelled by purpose and 6 priority tiers	Not its focus; you supply the user-agent string
Advantage AI Crawler Check. Detects a firewall turning crawlers away	Yes, reports a WAF or challenge page separately from a robots.txt block	Shows the response code your own machine receives, which may differ from what a data-centre crawler gets
Advantage Screaming Frog SEO Spider. Works on private or staging sites	No. Public URLs only	Yes, from inside your network

Dot colour shows which tool has the edge on that row: AI Crawler Check, Screaming Frog SEO Spider, comparable.

Two crawlers that answer opposite questions

Screaming Frog and AI Crawler Check are both crawlers, which is why people compare them, but they point in opposite directions. Screaming Frog holds the user-agent fixed and varies the URL: it pretends to be one bot and walks your whole site. AI Crawler Check holds the URL fixed and varies the user-agent: it takes one address and asks how every bot in our database would be treated.

Once you see that, the choice is usually obvious. If you are migrating a site and need to know which of 40,000 product pages Googlebot will lose under a new rule, you want Screaming Frog. If a client asks "are we visible to ChatGPT, Claude, Perplexity and Gemini?", you want a matrix of crawlers, and that is the job our free AI crawler check was built for.

What Screaming Frog does better

We would rather say this clearly than have you discover it later. For whole-site crawl analysis Screaming Frog is the stronger tool, and it has been the industry reference for years.

Every blocked URL, with the reason. The Blocked by Robots.txt filter shows each disallowed URL and the robots.txt line that matched it. We test addresses you give us; we do not discover every URL on your site.
Safe experiments. With a licence, the custom robots.txt feature lets you edit rules and see the effect on a real crawl before anything goes live. That is a genuinely useful way to avoid an expensive mistake.
Breadth. One crawl also reports broken links, redirects, titles, hreflang, rendering and structured data. Our audit is deliberately narrower.
Private sites. It runs on your machine, so it can reach a staging server we never could.

Where a desktop crawl can mislead you about AI crawlers

There is one trap worth knowing. When Screaming Frog crawls, the request comes from your computer and your IP address. Many sites put a bot manager or firewall in front of the origin that treats a request differently depending on where it comes from. Your office connection may get a normal 200 response while a real GPTBot request from a data centre gets a challenge page or a 403.

We have seen this pattern in our own case studies, where large publishers answered our Googlebot-style request with HTTP 403 because it did not come from Google's published IP ranges. A crawl from your desk cannot show that, because your desk is not where the crawler lives. An outside-in check from cloud infrastructure is closer to what an AI crawler actually experiences, and our report separates a firewall refusal from a robots.txt rule so you fix the right layer.

A workflow that uses both

Start wide with AI Crawler Check. Run the homepage and a few key templates. You get the crawler matrix in a minute and learn which bots, if any, are refused.
Go deep with Screaming Frog. For any bot that matters and is partially blocked, set it as the user-agent and crawl the site to list every affected URL.
Draft the fix. Use the custom robots.txt feature, or our robots.txt generator, to write the change.
Verify from outside. After publishing, run the check again to confirm the live result matches the plan, including at the firewall.

Setting up an AI crawler test in a desktop crawler

If you want to use Screaming Frog for a deep AI crawler investigation, a few settings make the result more meaningful:

Use the exact user-agent string. robots.txt matching uses the product token, such as GPTBot or ClaudeBot. Copy the string from the operator's own documentation or from our AI bot directory, which links to it.
Crawl once per crawler that matters. A training crawler and a search crawler from the same company can be treated differently. Test both if your rules name them separately.
Remember the network difference. Your crawl still comes from your own connection. Treat any firewall result as provisional until it is confirmed from outside.
Turn off JavaScript rendering for AI checks. Many AI crawlers read raw HTML only. Comparing a rendered crawl with a raw one shows which content they may miss.

That last point is often the most valuable. A page can be fully allowed by robots.txt and still be close to empty for a crawler that does not execute scripts. Our check reports whether key content is present in the raw HTML, and a desktop crawl with rendering switched off lets you investigate the same issue across every template on the site.

Where we would send you elsewhere For whole-site crawl analysis, draft robots.txt testing against a real crawl, or auditing a staging server, use Screaming Frog SEO Spider. Come back for the multi-crawler view and the outside-in verification.

Frequently asked questions

Can Screaming Frog test AI crawlers like GPTBot?

Yes, one at a time. You can set a custom user-agent string and crawl as that bot. What it does not do is test many crawlers in one run or tell you what each bot is for. AI Crawler Check tests 265 at once and labels each by purpose.

Is the free version of Screaming Frog enough?

For small sites, often yes. The free version crawls up to 500 URLs. The custom robots.txt editor and unlimited crawling need a paid licence, which was $279 per user per year when we checked on 2026-10-18.

Why does my Screaming Frog crawl succeed but AI crawlers are blocked?

Usually a firewall or bot manager. Your crawl comes from your own IP address, while real AI crawlers come from data centres and are often treated differently. Run an outside-in AI crawler check and look for a firewall or challenge result rather than a robots.txt block.

Does AI Crawler Check replace a full SEO crawler?

No. It is a focused AI crawler and GEO audit. For broken links, redirects, hreflang and full-site analysis, a desktop crawler such as Screaming Frog is the right tool.

See where your site actually stands

Free check against 265 AI crawlers. No sign-up, nothing to install.