llms.txt checker.
Enter a website URL and we’ll retrieve its public llms.txt file so you can see exactly what AI systems can read. This is a live-file check, not a specification score.
One public URL
Check the exact file AI tools can request.
Plain text preview
Read the raw Markdown without any transformation.
Instant feedback
Get a clear error when the file is missing or unreachable.
How to use it
Enter a site. Read the live file.
- 1. Paste a domain or a full /llms.txt URL.
- 2. We request the public file and follow same-host redirects.
- 3. If it is reachable text, you see the raw Markdown, line count, and the final URL.
- 4. If it is missing or the wrong type, you get a specific error instead of a false pass.
What we report
Reachability first. Format second.
A file can exist and still be difficult to use if it is blocked, empty, or wrapped in HTML. This checker gives you a human-readable view of the live response. For heading order and file lists, use the specification guide.
Reachability
Confirms that the expected public URL responds successfully.
File contents
Shows the raw Markdown without rendering or rewriting it.
Quick diagnosis
Names the failure: missing, HTML, empty, redirect, timeout, or too large.
Valid-looking sample
After a fetch, the body should look like this.
We do not grade this automatically. If the live file starts with an H1 and uses Markdown lists, you are in the right shape.
# Example Company
> A concise summary of what the company does and who it serves.
## Start here
- [Overview](https://example.com/): The main introduction to the company.Error glossary
What the messages mean.
No file (404)
Nothing is published at /llms.txt, or the path is wrong.
HTTP error
The server responded with a non-success status other than 404.
HTML instead of text
The URL returned a web page. Agents need text/plain or text/markdown.
Empty file
The response succeeded but the body had no content.
Off-site redirect
The request left the original host. That is treated as a failed check.
Timeout
The origin took longer than 10 seconds to respond.
Too large
The file exceeds the display limit (2 MB).
Unreachable host
DNS, TLS, or network failure before a useful response.
Checker, validator, or tester?
They all start with the same useful question.
Ranked tools for this query are mostly format validators. This page is a live-file checker: it answers whether AI systems can retrieve your public llms.txt and what that response contains.
If the file is missing, the llms.txt generator can discover your pages and create a starting point. Unlock the full file before you publish.
Create a missing fileCommon questions
Questions about the llms.txt checker.
What does this llms.txt checker actually test?
It fetches the public file and shows the raw body when the response is reachable text. It reports 404, HTML instead of text, empty files, off-site redirects, oversized files, and timeouts. It does not score the Markdown against the official specification.
Is this an llms.txt validator?
People search for checker, validator, and tester interchangeably. Format validators grade headings and lists. This tool is a live-file checker. After a successful fetch, compare the body with the specification guide.
What URL should I enter?
A website such as example.com, or a full https://example.com/llms.txt URL. If the path is not already llms.txt, the checker requests /llms.txt on that origin.
Why did the checker say it found HTML?
The path returned a web page, often a 404 template or a CMS wrapper, instead of a plain Markdown file. Fix the Content-Type and make sure the file is not rendered through a theme.
The file is missing. What next?
Create one from your website, publish the complete file at /llms.txt, then run this checker again. Do not publish an incomplete generator preview.
Keep exploring
More useful llms.txt resources.
Move from the format to implementation, examples, and a live check without losing the thread.