AI SEARCH & BOTS
llms.txt Validator
llms.txt is a proposed file at a site’s root that gives language models a short Markdown map of the site: what it is and which pages matter. The format is simple but easy to get slightly wrong. This validator checks a file against the proposal.
- Runs in your browser
- Nothing you paste is uploaded
- Free, no sign-up
- CheckH1 title on the first line
- CheckBlockquote summary
- CheckH2 sections
- CheckLink items in "- [name](url): notes" form
Free
no sign-up, no usage limit
0 uploads
what you paste stays on your device
5 checks
what the tool looks at
Offline
works once the page has loaded
Loading the tool…
HOW IT WORKS
How to use the llms.txt Validator
The contents of an llms.txt file.
Open yoursite.com/llms.txt and copy its contents.
Paste them here and fix the problems.
Publish the corrected file at the same address.
WHAT IT CHECKS
What it looks at, and how to read it.
Checks on the structure, and each section with its link count and problems.
What it checks
- H1 title on the first line
- Blockquote summary
- H2 sections
- Link items in "- [name](url): notes" form
- Relative and duplicate links
How to read the results
- Problems break the format; warnings are improvements.
- The "Optional" section marks links a model may skip.
The concepts behind it, in the SEO glossary: llms.txt.
GOOD TO KNOW
Common mistakes, an example and the limits.
Common mistakes
- Pasting a sitemap’s URL list without names or notes.
- Relative links that do not work when the file is read on its own.
- H3 sub-headings, which the format does not use.
A worked example
A file with a title and two sections, one with items written as plain URLs: the validator lists the lines to turn into Markdown links.
Limitations
- llms.txt is a proposal (llmstxt.org); no major AI product has said it reads the file.
- Checks the format, not whether the linked pages exist.
FAQ
Questions about the llms.txt Validator
Straight answers about what it does and where its limits are.
Do I need an llms.txt?
No. It is optional and no major AI product has said it uses it. It is cheap to publish if you want a curated map of your site.
Is llms.txt like robots.txt?
No. robots.txt controls crawling. llms.txt only suggests what to read; it blocks nothing.
Need this for a whole website, over time?
The NdovuSEOLabs platform connects your own Search Console, analytics and server logs, and audits every page on a schedule.