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llms.txt Checker
Does the file exist, is it valid, and are the companion files there? Check any site in two seconds.
Validates against the llmstxt.org format: plain text, H1 title, markdown page links — plus llms-full.txt, agents.json and prompt.txt presence.
Questions
- What does this checker validate?
- Four things: the file exists at /llms.txt, it's real plain text (not an HTML soft-404), it follows the llmstxt.org shape — an H1 title and markdown links mapping key pages — and whether the companion files (llms-full.txt, agents.json, prompt.txt) are published alongside it.
- My llms.txt exists but shows as invalid — why?
- The most common failures: the server returns your 404 page with a 200 status (HTML instead of text), the file has no `# Title` heading, or it contains prose without any `[Title](url)` page links. The checker names the exact problem it found.
- Do AI companies actually read llms.txt?
- Honest answer: it's an open proposal (llmstxt.org), not a confirmed standard — no major AI company documents it as a signal. It costs minutes to publish correctly and may pay off; treat it as a cheap bet, not a guarantee.
- How do I create a valid llms.txt?
- Our free generator crawls your site and writes one from your real pages — correct H1, sections, and per-page links with descriptions. Run it from the homepage, then re-check here.
Missing or invalid? Generate a correct one free.
The generator crawls your real pages and writes the file for you — plus your AI Visibility Score.
Generate llms.txt →