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llms.txt checker

The llms.txt checker fetches your /llms.txt file, validates its format against llmstxt.org and tests the URLs it links to. A generator tab builds a new file in your browser. We fetch only /llms.txt, /llms-full.txt and the linked URLs. We do not store your page text. Google Search does not use llms.txt, and no answer engine is shown to rely on it.

By SeenLens · Last updated

Free, no sign-up. We fetch /llms.txt, /llms-full.txt and up to 10 linked URLs. We do not store the files.

What does the llms.txt validator check?

Checks the llms.txt validator runs
CheckWhat it looks at
FetchHTTP status, content type and file size of /llms.txt
TitleAn H1 heading on the first line
SummaryA blockquote (>) summary under the title
SectionsH2 headings that group the links
Link listsEach link item is a Markdown link in a list, with optional notes after a colon
URLsLinks use absolute URLs
Linked pagesUp to 10 linked URLs return status 200
Full fileWhether /llms-full.txt exists (noted only, not validated)

The llmstxt.org format requires only the H1 title. The summary, the notes and the H2 sections are optional parts of the format. Treat a missing optional part as a style choice.

What does a valid llms.txt example look like?

This example follows the llmstxt.org format. It is a Markdown file served at the root of the site:

https://example.com/llms.txt
# Example Co

> Example Co makes scheduling software for dental clinics. This file lists the pages that explain what the product does and how it is priced.

Prices are in US dollars. Support pages are in English.

## Product

- [How it works](https://example.com/how-it-works.md): The booking flow in four steps
- [Pricing](https://example.com/pricing.md): Plans and limits

## Docs

- [API reference](https://example.com/docs/api.md): REST endpoints and authentication

## Optional

- [Company history](https://example.com/about.md)

The format has an H1, a blockquote summary, optional notes without headings, and H2 sections of links. By convention, an H2 section named Optional holds links an agent can skip when it needs less context. The file can sit at /llms.txt or at a subpath such as /docs/llms.txt.

How does the llms.txt generator work?

Open the generator tab, enter your site name, a one-sentence summary and your key pages, and the tool writes an llms.txt file in your browser. Copy it to the root of your site, then run the checker on the live URL. The generator does not send your inputs to a server. Keep the file short and link only to pages you want an AI tool to read first.

How do I read the result?

  • HTTP 404 on /llms.txt. The site has no file. This is a valid state, because the file is optional.
  • HTTP 200 with an HTML content type. The server may return a soft 404 page or a web page instead of Markdown. Serve the file as plain text or Markdown.
  • Missing H1. Put the site or project name in an H1 on the first line.
  • Relative or broken links. Use absolute URLs, and fix any linked page that does not return 200.
  • Large file. The file is meant to fit in a model context window. Keep only the key pages in it.

How do I fix a failed check?

Frequently asked questions

Does Google use llms.txt?

No. Google's guide to generative AI features says Google Search does not use llms.txt files. It says they neither help nor harm your Search visibility.

Does ChatGPT read llms.txt?

OpenAI's crawler documentation does not mention llms.txt. An Ahrefs study of 137,210 domains (May 2026) found that 97% of llms.txt files received no requests at all. GPTBot was the most frequent named AI fetcher among the files that were read.

Where does the llms.txt file go?

At the site root: https://example.com/llms.txt. The llmstxt.org format also allows a file at a subpath such as /docs/llms.txt, which covers the URLs under that path.

Who invented llms.txt?

Jeremy Howard proposed it on 3 September 2024. It is a community proposal at llmstxt.org. See what llms.txt is.

Is llms.txt the same as robots.txt?

No. The robots.txt file tells crawlers which paths they may fetch. The llms.txt file lists pages that are worth reading. It controls nothing and blocks nothing. See llms.txt vs robots.txt.

Do I need llms.txt to appear in AI answers?

No evidence shows that you do. Crawler access, indexing and clear content come first. Run the AI crawler checker before you work on llms.txt.

Method and sources

The checker follows the llmstxt.org format. SeenLensBot fetches /llms.txt, notes whether /llms-full.txt exists, and requests up to 10 linked URLs. Last reviewed 2026-11-06.

Sources