Free tool

Free llms.txt Checker

Half Dev fetches /llms.txt from your site's root and checks that it is a plain-text file starting with a title heading. It is the largest single check in the GEO score, worth 18 of 100 points. No API calls, no cost.

llms.txt

  • — A file exists at /llms.txt (an error response fails)
  • — It is plain text, not an HTML page served with a 200
  • — It starts with a # title heading, as the llmstxt.org format expects
  • — Links in the file are counted and reported, not scored

Every scan scores all three areas — SEO, AEO and GEO — so you get the full picture in one go.

Looking for something more specific? Free GEO Checker (llms.txt & FAQ Schema)

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About the llms.txt checker

llms.txt is an informal, community-proposed file that sits at the root of a site, like robots.txt, and gives AI tools a short, curated map of the pages that matter most. The format described at llmstxt.org starts with a title heading, usually followed by a short summary and lists of links. This checker fetches /llms.txt from the site you submit and tells you whether it exists, whether it is a real text file rather than a web page, and whether it starts with a title heading. It does not check that your links work, judge the quality of the summary, or show that any AI tool reads the file. It is a convention that some sites have adopted, not a specification from any AI provider, and support varies.

How the llms.txt checker works

  1. You submit a page URL, and Half Dev fetches /llms.txt from that site's root.
  2. A plain-text file that starts with a title heading earns the full 18 points. A text file without a title heading earns 9. A missing file, an empty file, an error response or an HTML page earns 0. A file that cannot be read, such as one that times out, is left out of the score instead of failed.
  3. The other 82 points of the GEO score come from seven other signals, such as the AI bot split, entity markup and FAQPage schema, so you get a score out of 100 and a note on each part.

How the llms.txt check is scored

The llms.txt check is worth 18 of the 100 points in the GEO score. The other 82 come from seven other signals, including FAQPage schema, entity markup and the AI bot split in robots.txt. The companion /llms-full.txt file is its own check, worth 6.

A plain-text file with a title heading scores the full 18. A text file without a title heading scores 9. Anything else scores 0. A file that cannot be read, such as one that times out, is left out of the score instead of failed.

18 points

Text file with a title heading

Full credit for this check.

9 points

Text file, no title heading

Half credit. Add a title line at the top.

0 points

Anything else

The check earns nothing.

How to fix your llms.txt file

No file, or a 404

Nothing is served at /llms.txt. The check scores 0.

Fix: Create the file and serve it from the root of your domain. A file inside a subfolder is not what the checker looks for.

A web page served at /llms.txt

The address returns an HTML page with a 200 status, often your 404 page. The checker treats this as not a file and scores 0.

Fix: Make /llms.txt return plain text, or remove the route if you do not have a file. Check the response in your browser. It should look like text, not like a styled page.

An empty file or an error response

An empty file scores 0. A response such as 403 or 500 means the file cannot be read, and also scores 0.

Fix: Add content, or fix the server rule that is refusing the request.

A text file with no title heading

The file exists and is plain text, but its first line does not begin with # followed by a name. It scores 9.

Fix: Make the first line a single title heading, for example # Your Site Name.

Example of a valid llms.txt file

A minimal llms.txt in the expected shape. A file that starts like this earns the full 18 points. The checker looks for the title line at the top.

# Example Co

> Example Co makes invoicing software for freelancers.

## Docs

- [Getting started](https://example.com/docs/start): Set up your first invoice
- [API reference](https://example.com/docs/api): Endpoints and authentication

Who needs an llms.txt file

  • A site owner who read about llms.txt checks whether the file they added is being served correctly.
  • A developer who just deployed a site finds out that /llms.txt returns the 404 page with a 200 status.
  • An SEO consultant adds an llms.txt check to a client audit.

What the llms.txt checker does not check

  • The score on this page comes from /llms.txt only. A scan also reads /llms-full.txt, which is its own GEO check worth 6 points and never changes your llms.txt result. Other variants are not looked for.
  • It checks that the file exists, is plain text and starts with a title heading. It does not check that your links work or that the summary is accurate.
  • It cannot show that any AI tool reads your file. llms.txt is a proposed convention, not an official standard, and support varies.
  • It does not allow or block anything. Access rules belong in robots.txt.

FAQ

An informal, community-proposed file, similar in spirit to robots.txt, that gives AI systems a short, curated map of a site's key content. It was proposed in 2024 and is written in Markdown.

At the root of your domain, for example https://yourdomain.com/llms.txt. A file in a subfolder is not what this checker looks for.

A plain-text file that starts with a title heading gets 18 of 18 GEO points. A text file with no title heading gets 9. A missing file, an empty file, an error response or an HTML page gets 0. The other 82 points come from the seven other GEO signals.

There is no guarantee. It is not an official standard, support varies between AI tools, and nobody can promise it changes what they cite. It is a low-cost file to publish, which is the main argument for having one.

No. robots.txt tells crawlers what they may fetch, and a sitemap lists your URLs for search engines. llms.txt is a short, human-written summary with links, aimed at AI tools.

Not yet. For now this checker only tells you whether your site has one and whether it looks like the expected format.

Many sites answer unknown paths with their normal page and a 200 status. If /llms.txt shows your site's design in a browser, that is what the checker saw.

Yes. A scan reports whether /llms-full.txt exists and is plain text, and scores it as a separate GEO check worth 6 points. It never changes your llms.txt result.

Yes as a shape, but replace the name, summary and links with your own. A file that describes pages you do not have is worse than none.

Terms explained: llms.txt · Generative Engine Optimization · AI-Readable Content

Want the whole picture? See all three checkers.