# Who publishes llms.txt: a registry of sites

> A registry of sites checked for llms.txt, llms-full.txt and Markdown versions of pages, with the measurement date, adoption estimates and well-known sites without the file

Page: https://llms-full-txt.ru/en/reference/adoption/
Site index: https://llms-full-txt.ru/en/llms.txt

`llms.txt` is published first of all by developer documentation sites: OpenAI, Anthropic, Stripe, Cloudflare, GitHub. The bulk of files is created not by people but by platforms and plugins that switch the feature on for all their sites at once.

Adoption estimates range from 2% to 28%: they depend on which sites made it into the sample.

Publishing your own file does not mean a company reads other sites' files. No owner of an AI system has stated such a commitment.

## How many sites have the file

- 2.1%
- of sites in the HTTP Archive crawl: 8.7%
- of the top thousand sites: 28%
- of domains in a sample skewed towards an SEO audience: 584K
- files found in a single crawl of the web

The numbers do not contradict one another: they have different denominators. A crawl of the whole web gives about two percent. A sample of sites whose owners do SEO gives ten times more, and its authors call it an upper bound themselves.

Notes on the sources: [Web Almanac](https://llms-full-txt.ru/en/blog/web-almanac-2025-llms-txt/), [Common Crawl](https://llms-full-txt.ru/en/blog/common-crawl-584k-llms-txt/).

## Who creates the files

| Source of the file | Share | Where the number comes from |
|---|---|---|
| Made by a generator, not by hand | 68% | [Common Crawl](https://commoncrawl.org/blog) |
| Sites on Wix | 41% | Common Crawl |
| All in One SEO for WordPress | 39.6% | [Web Almanac 2025](https://almanac.httparchive.org/en/2025/seo) |
| Yoast SEO for WordPress | 3.6% | Web Almanac 2025 |

The shares come from different crawls and do not add up. The common conclusion: most files exist because a platform switched the feature on by default.

## Sites that were checked

The measurement was made by requests to the sites themselves. The table notes what each example shows and what it does not prove.

- [OpenAI](https://developers.openai.com/llms.txt): A root index plus nested files for /api, /codex, /commerce. Does not prove: that chatgpt reads other sites’ llms.txt.
- [Anthropic](https://platform.claude.com/llms.txt): A docs index and the full text in one file. Does not prove: that claude reads other sites’ llms.txt.
- [Cloudflare](https://developers.cloudflare.com/llms.txt): A very large index: the full text takes 67 MB. Does not prove: that a file this big is usable by an agent as a whole.
- [Stripe](https://docs.stripe.com/llms.txt): llms-full.txt is not required: an index and Markdown pages are enough. Does not prove: that skipping the full file is a general rule.
- [Cursor](https://cursor.com/llms.txt): The only measured site with rel=describedby from the second edition. Does not prove: that the second edition is widely adopted.
- [GitHub Docs](https://docs.github.com/llms.txt): An index without a full file on large docs. Does not prove: that copilot relies on this file.
- [Mintlify](https://www.mintlify.com/docs/llms.txt): The platform generates the files automatically for every site it hosts. Does not prove: the quality of each generated file.
- [Yandex Cloud](https://yandex.cloud/llms.txt): An example on a Russian site. Does not prove: that yandex search uses such files.

Checked October 3, 2026.

## Who does not have the file

On the measurement date `/llms.txt` answered `404` at:

| Site | Why it is notable |
|---|---|
| developers.google.com, developer.chrome.com, web.dev | Lighthouse checks for the file, but the team's own sites do not publish it |
| docs.astro.build, starlight.astro.build | often cited as examples in older lists |
| developer.mozilla.org, the root of huggingface.co | the same |
| tailwindcss.com | developer documentation without the file |
| ahrefs.com, moz.com | they study the format but do not publish it |

The list is a useful correction to "who supports `llms.txt`" directories: they age fast and are rarely rechecked.

## The second edition

The [second edition of the proposal](https://llmstxt.org/) came out on August 10, 2026 and added discovery relations: `rel="describedby"` and `rel="alternate"`. Among the measured sites `rel="describedby"` appeared on one. Documentation platforms still send headers of their own that are not in the proposal.

What changed: [changes in the second edition](https://llms-full-txt.ru/en/specification/changes/), [discovery](https://llms-full-txt.ru/en/specification/discovery/).

## What follows from this

**Confirmed**

- Large documentation sites publish `llms.txt` and Markdown versions of pages.
- Most files on the web were created automatically.
- Not everyone publishes `llms-full.txt`: Stripe and GitHub Docs do without it.

**Not proven**

- That owners of AI systems read other sites' files: nobody has published such a commitment.
- That the second edition is widespread: the measurement shows isolated cases.

**What it does not mean**

- A well-known company having the file does not prove a benefit for another site.
- The number of published files is not the number of files read.

## How the measurement was made

- Date: {CHECKED.en}.
- Method: requests to `/llms.txt` and `/llms-full.txt`, a page request with `Accept: text/markdown`, inspection of the `Link` header and `rel` links in the HTML.
- The status code, content type and size were recorded.
- The answer depends on the client: some sites answer a command line and redirect a browser. The table records the answer given to a command line.

Repeat the measurement for your own site: [Validating files and markup](https://llms-full-txt.ru/en/guides/validation/).

## What to read next

- [Does llms.txt work](https://llms-full-txt.ru/en/guides/does-llms-txt-work/) - studies of requests to the files
- [Advanced examples](https://llms-full-txt.ru/en/examples/advanced/) - how real files are built
- [Status of the standard](https://llms-full-txt.ru/en/guides/standard-status/) - what a proposal is and who stands behind it