Free tool, runs in your browser
llms.txt generator and validator
Fill in the fields to get an /llms.txt in the proposed format, or paste a file you already have to check it. Nothing you type leaves your browser.
Check an existing llms.txt
Paste the contents of your file (open https://yoursite.com/llms.txt and copy everything).
Publish it, then check how it is served
Save the result as plain text at https://yoursite.com/llms.txt. A common failure is a host that answers unknown paths with the home page: the file then comes back as HTML and counts as absent. The free AI crawler check reports whether /llms.txt is present and served as text, along with which of 20 AI crawlers your site lets in.
What llms.txt does and does not do
llms.txt is a proposal for a short Markdown index of your most useful pages, written for AI tools. It does not grant or block access: that is still robots.txt and your CDN. It is not an IETF or W3C standard and nothing obliges an AI company to read it, so treat it as cheap documentation, not as a ranking factor. In our October 2026 study, about 1 in 10 popular sites published a valid one. The full format, a worked example and each finding above are explained in our llms.txt guide.
Written with AI. If you spot an error, write to [email protected].