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llms.txt Validator
Validate a site's llms.txt against the proposed format: a leading H1, a summary, H2 sections, and links with descriptions.
Public information only. Do not enter passwords, private URLs, or confidential data.
What this llms.txt validator checks and how to act on it
An llms.txt validator checks a site's /llms.txt against the proposed format: a leading H1 with the site name, a summary blockquote, H2 sections, and links written as "- [Title](URL): description". This tool reports missing elements, links without descriptions, external links, and very long files.
In our October 2026 study, 240 of 663 sites ranking for SEO queries served a conforming llms.txt, and another 71 served a file that did not follow the format. No major AI search engine has said it uses llms.txt to choose sources, so treat a valid file as a convenience for agents and tools, and keep it short, curated, and generated from your page registry.
How to use the llms.txt validator
- Enter your site URL.
- The validator fetches /llms.txt and checks the H1, summary, sections, and link format.
- Add descriptions to links and curate long files.
What it does not check
- Whether any AI system reads the file.
- Whether each linked URL is live.
Read the guide
Step-by-step explanations of what this tool checks and how to fix what it finds.