How to write an llms.txt file
A plain-text index of your best pages for AI assistants: an H1, a summary line and sections of Markdown links. It takes about ten minutes; treat it as a cheap bet, not a ranking factor.
Step by step, with screenshots: llms.txt: what it is, who reads it and how to write one →
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What it is
llms.txt is a plain-text Markdown file at the root of a site, /llms.txt, that lists your most useful pages with a short description each, so AI assistants and tools can find the important content quickly. The format was proposed in September 2024 at llmstxt.org.
It is optional and unproven: some developer tools and documentation sites read it, but no major AI assistant has confirmed using it and Google has said Search does not. It takes about ten minutes to write, so treat it as a cheap bet and do not expect ranking changes.
OK looks like this: the file answers 200 as text, starts with an H1 with the site name, has an optional one-line summary, then sections of Markdown links with short descriptions. getReport checks whether the file exists and whether its format is readable.
What a passing site looks like
- llms.txt follows the llmstxt.org formatwarning · −0.5 ptseffort S
- llms.txt foundinfo onlyeffort S
1. llms.txt format
Why it matters. An llms.txt that is not in the expected shape (an H1 first, links grouped under sections, served as text) is skipped by the tools that read it, so it does nothing.
- Start the file with "# Site name", follow with an optional "> summary" line, then "## Section" headings each holding "- [Page title](https://…): one-line description" entries.
- Serve it with a text/plain or text/markdown content type and keep it under 100 KB; put long content in /llms-full.txt instead.
2. llms.txt file
Why it matters. /llms.txt is a plain-text index of your most useful pages written for AI assistants, in the format proposed at llmstxt.org. It is optional and new: a few tools read it, but no major assistant has confirmed using it and Google has said Search does not. It costs about ten minutes, so treat it as a cheap bet, not a ranking factor.
- Create /llms.txt: an H1 with the site name, a one-line blockquote summary, then "## Section" headings with Markdown links to your key pages and a short description each.
- Serve it as text/plain or text/markdown; optionally add /llms-full.txt with the full text of those pages.
Questions people ask
What is llms.txt?
llms.txt is a proposed standard file that gives large language models a curated, Markdown-formatted map of a website: a title, a short summary and lists of links to key pages with one-line descriptions. It is meant to help AI tools find the right content without parsing every HTML page.
Where do you put the llms.txt file?
At the root of your domain, so it opens at https://example.com/llms.txt, the same place as robots.txt. Serve it as text/plain or text/markdown and keep it public. An optional /llms-full.txt next to it can hold the full text of those pages in one file.
What is llms-full.txt?
llms-full.txt is an optional companion file that contains the full text of the pages listed in llms.txt, in Markdown, so an AI tool can load everything in one request. It is useful for documentation sites; for most business sites, a short llms.txt is enough.