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llms.txt Validator

Check an llms.txt file against the spec and list what's missing or malformed.

llms.txt

How it works

  1. 1

    Paste the file or enter a domain to fetch /llms.txt.

  2. 2

    The validator checks for a single H1, a blockquote summary, H2 sections, and Markdown links with absolute URLs.

  3. 3

    Each finding is marked as an error or a warning with the line it refers to.

Questions

What makes an llms.txt invalid?

No H1 title, more than one H1, or link lines that aren't Markdown links. Missing summaries and relative URLs are warnings.

Is there an official llms.txt validator?

The proposal doesn't ship one. This tool applies the structure the proposal describes.

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