llms.txt Validator
Ensure your llms.txt file is perfectly structured for AI crawlers. Test for syntax, hierarchy, and retrieval efficiency.
Paste Your Content
Paste the contents of your llms.txt file below to check for common issues.
Frequently Asked Questions
What does the llms.txt validator check?
It checks structural rules the spec requires — a single H1, a blockquote summary immediately below it, well-formed markdown link syntax, an Optional section for lower-priority links — plus practical issues the spec doesn't enforce but that determine whether the file is useful, like file length and whether links are present at all.
Why would my llms.txt file fail even if it looks correct?
The most common silent failures are a missing blockquote summary, a file with no markdown links (just plain text or bare URLs), or a file that's grown too large for models to reliably use in full. None of these are obvious from a quick read.
Is an llms.txt validator the same as an llms.txt checker?
Yes — "validator" and "checker" are used interchangeably. Both describe a tool that verifies your file against the llms.txt format spec.
How often should I re-validate my llms.txt file?
Any time you change URLs, launch a page you want AI models to prioritize, or restructure navigation — the same way you'd treat a sitemap.xml regression check.