Paste your llms.txt content and get instant feedback on format correctness, required sections, link structure, and common mistakes that break AI crawler readability.
Paste your llms.txt content on the left and click Validate to see a full breakdown of issues and passes.
What does this validator check?
The validator checks for: a required title line (# Your Site), a blockquote description (> Your description), at least one section header (## Section), at least one page link in the format - [Title](URL), valid URL syntax in all links, no broken link formats, and overall structure following the llms.txt standard.
Why does format matter for AI crawlers?
AI crawlers that read llms.txt, such as Perplexity's live-web index, parse the file programmatically. Malformed headers, missing descriptions, or broken link syntax can cause the file to be partially or fully ignored. A clean, valid llms.txt ensures the crawler correctly identifies your most important pages. Pair it with our generator to build one from scratch.
My file passes validation but I'm still not visible in AI results. Why?
llms.txt is one signal among many. AI visibility also depends on off-site citations (backlinks, Reddit mentions, LinkedIn posts), structured data (schema markup), and content quality. Check our complete GEO guide for the full picture. Also make sure you are not accidentally blocking AI crawlers with your robots.txt using our Robots.txt Checker.