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Free Robots.txt Validator
Enter your domain. We fetch your robots.txt and flag the issues that actually matter — a site-wide block, a missing sitemap declaration, or crawlers silently locked out.
This checks 1 thing. HellSEO's full audit scores 24 checks across SEO, AEO, and GEO — including backlink authority and score history this page doesn't cover.
See Full ScoreHow It Works
We fetch your robots.txt and check the things that actually break crawling: whether the file exists, whether a User-agent: * group blocks everything with Disallow: /, and whether your sitemap is declared.
We also check whether any named AI crawler is specifically blocked, since that's increasingly common and easy to miss — a summary count is shown here, with full detail in the AI Crawler Access Checker.
This reads your robots.txt only — no crawling of your actual pages, no data stored.
Who Uses This
New site launches
Catch a staging-only Disallow: / before it ships to production and de-indexes the whole site.
Agencies & audits
Quick first check before a full technical SEO audit — confirms the basics are in place.
CMS migrations
Verify the new platform's default robots.txt didn't quietly reintroduce a block or drop the sitemap declaration.
Frequently Asked Questions
What's the most common robots.txt mistake?
A leftover Disallow: / from a staging environment that never got removed after launch — this blocks every crawler, search engines included, and usually goes unnoticed for months.
Do I need a sitemap declared in robots.txt?
It's not required — crawlers will try /sitemap.xml by default — but declaring it removes the guesswork and lets you use a non-default filename or location.
Does a missing robots.txt hurt SEO?
Not directly. No robots.txt means 'crawl everything,' which is usually fine. But you lose the one place to declare your sitemap and block AI crawlers deliberately instead of by accident.
Can I test a single crawler like GPTBot?
Yes — use the AI Crawler Access Checker for a breakdown of which specific AI bots are blocked, since this validator focuses on general robots.txt health.
Want the full picture?
This tool checks one thing. A full HellSEO audit scores your site across SEO, AEO, and GEO — and gives you ready-to-paste fixes.
Run a Full Audit