llms.txt Validator
Fetch any website's llms.txt and validate it against the llmstxt.org v2 specification — structure, required sections, link formats.
Frequently Asked Questions
What does the validator check?
It fetches the site's llms.txt and checks the v2 spec requirements: H1 title (required), blockquote summary (recommended), markdown link format, H2 sections, and whether the file is plain markdown rather than HTML.
Why does my site return HTML when I request /llms.txt?
Many SPA frameworks serve a fallback page for unknown routes, so /llms.txt returns the homepage HTML. You need a real markdown file at that path — see our llms.txt Generator to create one.
Is the H1 really required?
Yes. In the llmstxt.org v2 spec, the H1 with the site or project name is the only required section. Everything else is optional but recommended.
What counts as a valid link?
Standard markdown links pointing to http(s) URLs: [Title](https://example.com/page). Links with empty titles or non-http protocols are flagged.
How is compliance scored?
Each check contributes points: H1 (30), blockquote (20), links (25), H2 sections (15), Optional section (10). 100 means fully compliant with the v2 spec.