llms.txt
llms.txt is a proposed root-level file offering a curated, machine-readable map of a website's content for large language models.
In full
The llms.txt proposal, published in September 2024, describes a markdown file at a site's root providing background on the site and links to clean versions of its key pages, intended to help large language models find and read the content efficiently. A companion expanded variant is commonly called llms-full.txt. Adoption has grown but remains a minority practice among large sites. No major consumer AI search provider has confirmed using it as a retrieval or ranking signal, and Google's published guidance on its AI features states explicitly that such files are ignored. It has found genuine traction in one place: coding assistants and developer tools routinely fetch it when pointed at documentation.
Why it matters
It costs very little to publish and is genuinely useful if you ship technical documentation. It should not be presented as a meaningful lever for AI visibility, because there is currently no evidence that it is one.
A common misconception
That llms.txt is an AI equivalent of robots.txt or a sitemap with comparable standing. It is a proposal with limited adoption and no confirmed consumer support.