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Make or check your llms.txt in a minute. It’s a short file that tells AI assistants what your site is about and which pages matter. We check it against the official spec and Chrome’s Lighthouse test.
It gives them a short map of your site, so they find key pages fast. OpenAI, Anthropic, Google, Perplexity and xAI publish one for their own developer docs.
Google’s AI optimization guide (updated July 10, 2026) says Google Search ignores llms.txt. It won’t help or hurt your rankings there.
Google’s AI optimization guideIn an Ahrefs study of 137,210 domains, 97% of llms.txt files got zero requests in May 2026. That’s Ahrefs data, from a sample that leans towards SEO-savvy sites.
The Ahrefs studySo: a quick job worth doing, not a growth hack.
Since version 13.2 (May 2026), Chrome Lighthouse checks /llms.txt in its Agentic Browsing category. It only looks at the file in your site’s root. The file passes when all three rules hold:
No file at all (a 404) is fine: Lighthouse then skips the check. A server error (5xx) or “too many requests” (429) counts as a fail.
Our own llms.txt failed the link rule until October 2026, because it listed pages as “Name: URL”. Our checker copies the rules from Lighthouse’s source code.
Lighthouse’s llms.txt auditHere’s a short example with the five parts the spec describes.
# Example Shop > Example Shop sells handmade ceramics and ships across Europe. Prices include VAT. Orders ship within 3 working days. ## Shop - [All products](https://example.com/shop.md): Every item with price and stock - [Shipping](https://example.com/shipping.md): Costs and delivery times ## Optional - [Blog](https://example.com/blog): Stories from the studio
Put the file at yoursite.com/llms.txt. Since v2 you can also put one in a folder, like /docs/llms.txt. It then covers the pages in that folder.
The llms.txt proposal on llmstxt.orgOpenAI, Anthropic and Perplexity don’t say their crawlers use it. Their bot documentation points to robots.txt instead. Ahrefs did see GPTBot and ClaudeBot fetch some files, but rarely.
In the root of your site, so it opens at yoursite.com/llms.txt. A file in a folder, like /docs/llms.txt, covers only that folder.
One big file with all your docs in it, made popular by docs platforms such as Mintlify. It’s not part of the llmstxt.org spec. Our tool only checks whether you have one.
No. Spec v2 suggests them (page.md or page.html.md), and docs sites often have them. For most websites, linking to normal pages is fine.
No. robots.txt says which bots may crawl what. llms.txt doesn’t block or allow anything: it’s a reading guide, not a rulebook.
No. Google says Google Search ignores llms.txt, and that having one neither helps nor harms your visibility there.
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