llms.txt validator
Check a website
Type a website address. We'll look for its llms.txt file and tell you, in plain English, what to fix.
Don't have a file yet? Create one with our free generator. Want the bigger picture? Check your whole site's AI readiness.
What is llms.txt?
A short text file at yoursite.com/llms.txt that tells AI assistants (like ChatGPT, Claude and Perplexity) what your website is about and which pages matter most. Think of it as a menu for AI tools.
What we check
- The file exists and is a real text file, not a web page
- It starts with your name as a title:
# Your name - It lists your key pages under headings, with full web addresses
- Optional extras: a one-line summary and an llms-full.txt file
How scoring works
Based on the llms.txt proposal. Every file starts at 100. Each "must fix" costs 40 points and each "should fix" costs 10. Tips are free. A missing file or a web page scores 0.
| Check | Level | Points | What it means |
|---|---|---|---|
| File is empty empty |
Must fix | score 0 | The address returned nothing. Publish your llms.txt content there. |
| Web page instead of a file html |
Must fix | score 0 | The address returned a web page (HTML). Your site doesn't have an llms.txt yet, or it's in the wrong place. |
| Missing title no-h1 |
Must fix | −40 | The file must start with your site or project name as a heading: # Your name. |
| Title isn't first h1-not-first |
Must fix | −40 | Nothing may come before the # title line. |
| Note above the title preamble-before-title |
Should fix | −10 | A plain-text note (often added by SEO plugins like Yoast) sits above the # title. AI tools usually skip it, but the title should come first. |
| More than one title multiple-h1 |
Should fix | −10 | Use one # title. Use ## for section headings. |
| Served with the wrong type content-type |
Should fix | −10 | Servers should send llms.txt as text/plain or text/markdown. |
| File is very large large |
Should fix | −10 | Keep llms.txt short (under 1 MB). Put full content in llms-full.txt. |
| Empty section section-no-links |
Should fix | −10 | Each ## section should list pages as: - [Page name](https://url): short note. |
| Section with text only text-section |
Tip | 0 | A ## section that holds text but no links. That's fine for context; AI tools just won't find pages there. |
| No link sections no-sections |
Should fix | −10 | Add at least one ## section listing your most important pages. |
| Very few pages listed few-links |
Should fix | −10 | One or two links don't tell AI tools much. List your 3 to 10 most important pages. |
| Link isn't a web address bad-url |
Should fix | −10 | Links should be full web addresses (https://…) or paths on your site (/page). |
| Link is missing https:// missing-scheme |
Should fix | −10 | A link like example.com/page is read as a page on your own site. Write https://example.com/page. |
| Address repeats the domain repeated-domain |
Should fix | −10 | A link like https://site.com/site.com/page is broken. Remove the repeated domain. |
| Broken link format malformed-link |
Should fix | −10 | A list item that looks like a link but won't parse, e.g. brackets in the name or spaces in the address. |
| No summary line no-summary |
Tip | 0 | Optional but recommended: a one-line description after the title, starting with >. |
| Relative link relative-url |
Tip | 0 | Links like /pricing work, but full addresses (https://…) are safer for AI tools. |
| Insecure link http-url |
Tip | 0 | Links that start with http:// work, but https:// is preferred where the page supports it. |
| List items without links plain-list-items |
Tip | 0 | List items inside sections are most useful as links. |
| Has an Optional section optional-section |
Tip | 0 | AI tools may skip the ## Optional section when they're short on space. That's by design. |
A minimal valid example
# Example Co > Example Co makes scheduling software for clinics. ## Main pages - [Getting started](https://example.com/start): Set up in 10 minutes - [Pricing](https://example.com/pricing): Plans and prices ## Optional - [Blog](https://example.com/blog)
When your file passes, add your site to the directory for free, or let us check it every night.