llms.txt validator

What the validator checks

The checker follows the current llms.txt proposal. It looks for one H1 project name, the optional blockquote summary, H2 file-list sections, complete HTTP or HTTPS links, duplicate links, and the special Optional section.

Errors include a line number when the problem belongs to one line. Suggestions cover valid but thin files, such as a title with no summary or useful links.

A valid file does not prove the links work

When you enter a URL, this tool downloads that llms.txt file. It does not request the pages listed inside it, inspect their response headers, or confirm that an agent uses the file.

llms.txt is optional for AI search

The proposal gives systems that choose to read it a curated page list. Google says AI Overviews and AI Mode need no new machine-readable file or special AI markup. Pages still need the normal technical and content foundations used by Google Search.

Google's AI features guidance covers the current requirements and controls. A clean validation result does not predict crawling, indexing, rankings, citations, or traffic.

Create a cleaner draft

Fix a small file with the llms.txt generator. It creates the same basic shape from links you choose and can import page URLs from a sitemap.

Read the validation result

Errors break the format: no H1, more than one H1, links that are not full HTTP or HTTPS URLs, or list items that are not links. Fix those first. Suggestions point at a file that is valid but thin, such as a title with no summary or a section with no links. Each finding gives the line where it applies.

Fix common llms.txt problems

• Served as HTML. Some servers return an error page or a site template for /llms.txt. The validator shows what it actually received.
• Relative links. Write each link as a full URL.
• The whole sitemap pasted in. A long list defeats the point. Keep the pages an agent should read first.
• Links to pages that moved. Valid Markdown, broken result. Check the links when you change your site.

Check the links in your llms.txt with your agent

This page checks the file, not the pages it lists. The seo crawl command does both: it finds /llms.txt and checks that its links load. Ask:

Check whether example.com has an llms.txt with working links, and list the pages that are missing from it

The crawl runs from the CLI on your machine. Install it and run setup:

npm i -g seo && seo start

Or add the hosted MCP server to your agent and sign in with Google:

llms.txt validator questions