llms.txt Validator
Check your AI crawler index against the llmstxt.org specification
Source
Enter a domain (we'll try /llms.txt) or a direct /llms.txt URL
What this tool does
Checks your llms.txt file against the llmstxt.org specification. Validates H1 heading, blockquote summary, section headings, link syntax, file size, and URL validity. Returns a 0-100 score plus actionable fixes for every issue found.
Who it's for: Webmasters who publish llms.txt and want to confirm it parses cleanly; SEO/GEO specialists auditing competitor llms.txt files; developers automating llms.txt generation.
When to use
- •Validate your own /llms.txt before pushing to production.
- •Audit a competitor's llms.txt to learn best practices.
- •Debug a parser that rejects your llms.txt.
- •Verify automated llms.txt generators produce spec-compliant output.
How it works
- 1Enter your domain (auto-appends /llms.txt) or paste content.
- 2Parser extracts H1, summary, sections, and links.
- 3Each check marks pass / info / warning / error with a suggested fix.
- 4Score reflects severity: errors -25, warnings -8 from 100.
Tips
- •Keep your main /llms.txt under 10 KB; put expanded content in /llms-full.txt.
- •Use absolute HTTPS URLs everywhere - LLM clients often reject relative links.
- •Include an '## Optional' section for secondary/archived content.