llms.txt: Definition and Format

Who proposed llms.txt

llms.txt was proposed by Jeremy Howard and first published on llmstxt.org on September 3, 2024. It is a community proposal, not a standard from a search engine or an AI company, and support among AI tools varies.

What goes in the file

The proposal defines a simple, ordered Markdown format:

1. An H1 with the name of the site or project. This is the only required section.
2. A blockquote with a short summary containing the key information someone needs to understand the rest.
3. Optional paragraphs or lists with more detail.
4. Sections under H2 headings containing lists of links, each with an optional note about what the linked page covers.

The proposal also suggests offering clean Markdown versions of pages at the same URL with .md appended. Many sites additionally publish an /llms-full.txt with the full text of key pages; that is a common convention rather than part of the core proposal. You can see both on this site at lightspeedbolt.com/llms.txt and lightspeedbolt.com/llms-full.txt.

What the file does not do

llms.txt is read only by AI tools that choose to fetch it. It is not a Google ranking factor, and Google states that no special machine-readable files are needed to appear in AI Overviews or AI Mode; AI visibility still rests on indexable pages and third-party mentions. Our llms.txt guide covers whether it is worth adding and has a fill-in template.

Illustrative examples

Hypothetical scenarios that show how the term applies. They are not reports of real cases.

• A SaaS company's llms.txt opens with # Acme Invoicing, a one-line summary of who it serves, then H2 sections for Pricing, Docs and Comparisons with a link list under each.
• A documentation site publishes an llms-full.txt with the full text of its getting-started guides so coding assistants can load them in one request.