llms.txt Validator
Check whether a site's llms.txt exists, is linked from the page, and fits an agent's budget
Experimental Tool
This LLM & AI tool is experimental and under active development. Features and accuracy may vary. Use with caution in production environments.
Check a site
Enter any URL. This fetches the page and its /llms.txt, then reports whether the file exists, whether anything on the page actually links to it, and what it costs an agent to read.
What this checks, and why
Google has said plainly that Search does not use llms.txt, and a study of 137,000 domains found 97% of published files were never fetched at all. The reason is duller than it looks: no crawler guesses the path. A file nothing links to is a file nothing finds.
So the middle check is the one that matters. The other two only tell you whether what gets found is worth reading.
The full argument is in llms.txt isn't a protocol, it's a file.
Unlike the other tools here, this one calls a server, because a browser cannot read another site's HTML across origins. Only the URL you type is sent, and only public pages are fetched. Nothing is stored.