Header & Structure
Verifies single H1, blockquote summary, and formatted markdown section lists.
Enter a domain to test /llms.txt discovery, syntax, and link reachability.
Evaluated with proposal-grade governance according to official community specifications.
llms.txt is an evolving community proposal, NOT an official IETF or W3C web standard. We never claim it guarantees AI rankings.
We test real HTTP status codes on linked files rather than guessing their existence.
llms.txt serves as a concise directory of curated markdown links, while llms-full.txt contains the aggregated full text of documentation for direct model ingestion.
Through root placement (/llms.txt) and via rel='describedby' Link headers or link elements on key HTML pages.
Common causes include missing H1, missing blockquote summary, unbulleted link entries, or linked URLs returning 404/500 errors.
llms.txt interest is real, but the claim must be precise. Google Search does not use llms.txt for AI Search visibility. HTML&HTML validates it as an emerging machine-readable knowledge surface without treating it as a replacement for sitemaps, robots.txt, crawlable HTML or internal links.
robots.txt, sitemaps, canonicals, indexability and AI crawler access form the discovery foundation.
GEO, AEO, LLMO, entity graphs, schema and answer extractability reduce machine ambiguity.
RAG/retrieval, original information, E-E-A-T, freshness and evidence support source eligibility.
AAO, accessible journeys, intact links, measurable referrals and clear CTAs connect AI discovery to commercial action.
Recommendations, rankings, citations, traffic, customers and revenue are not guaranteed. HTML&HTML measures website-side technical and content blockers; it does not claim control over external AI systems.