What it does
An llms.txt file is easy to get slightly wrong. A stray line before the title, links written as bare URLs, or relative paths can make it harder for tools to read.
This checker reads your file the way the proposal at llmstxt.org describes it and scores it from 0 to 100. Every check that fails comes with a one-line fix.
How to use it
- 1Under “Check from”, choose “Fetch from a website” or “Paste the file”.
- 2Enter your domain in “Website or llms.txt URL”, or paste the text into “llms.txt content”.
- 3Press “Check llms.txt”. When you fetch from a website, it also tests up to 10 links that point to the same site, with a 5 second timeout.
- 4Work down the list. Each line shows “Pass” or “Fix”, what was found, and what to change.
What the score checks
The score adds up weighted checks. The title counts most, because it's the only part the proposal requires.
- Starts with an H1 title, with nothing before it.
- Exactly one H1, with sections as H2.
- A “>” blockquote summary under the title.
- H2 sections that each contain links.
- Links written as “- [name](url): notes” with full https:// addresses.
- Concise: 100 KB or less.
- Links resolve, when fetched from a website.
Fixes that matter most
Start with the title and the summary. A clear name and one sentence on what you do give any reader the context they need.
Then fix broken links. A link that returns an error is a dead end for any tool that follows it. Links to other domains are counted but not fetched, so check those yourself.
Pasted files are checked in your browser and their links aren't fetched. Use the fetch option once the file is live.
Questions
What score should I aim for?
80 or above means the file follows the proposal closely. A low score usually comes from one or two structural issues, and the fixes are short.
The checker says no llms.txt was found. Why?
It looks for /llms.txt at the root of the domain. If the address returns a 404, an error or an HTML page instead of plain text, the file counts as missing. Use the llms.txt generator to start one.
Will a perfect score improve my search rankings?
No major search engine has said it uses llms.txt for ranking. A clean file helps the AI tools that do read it understand your site.
What's llms-full.txt?
A common companion file that holds your full documentation as one markdown document. llms.txt stays short and links to detail. This checker only reads llms.txt.