Citare Tools · Free
llms.txt Validator
Validate any domain's /llms.txt against the llmstxt.org spec. 12 deterministic checks. 0-100 score with per-rule recommendations. Free, no signup, results in 3 seconds.
Free. No signup. Cached 24h.
Frequently asked
What does the llms.txt Validator check?
12 deterministic checks: file present at site root, sensible Content-Type, H1 title, blockquote summary, at least one H2 section, link-line format validity, absolute URLs, optional section, UTF-8 encoding, reasonable file size (200B-100KB), no HTML markup, and a reserved sample-URL-reachability slot. Each check has a weight; the final score is the weighted sum 0-100.
What's a good llms.txt score?
80-100: excellent — well-formed, spec-compliant, ingestible by AI engines. 60-79: solid foundation with minor polish available. Below 60: structural issues that may degrade AI ingestion. If your llms.txt is missing entirely, the score is 0 with band 'missing.'
Why does llms.txt matter in 2026?
OpenAI, Anthropic, and Perplexity all respect llms.txt directives. Cursor and Windsurf read it for project context. As of 2026 it's the most-adopted standard for AI ingestion hints. We audited Ahrefs, Profound, and Semrush in May 2026 — none ship llms.txt despite selling AI visibility tools. That's the credibility gap a working llms.txt closes.
Does the validator generate a llms.txt for me?
No — this is the validator. For generation, use our companion tool at /tools/llms-txt-generator (form-based, spec-compliant, paste-ready output). The validator is for checking an existing file's posture; the generator is for drafting a new one.
Is the score predictive of AI engine citation rate?
Indirectly. A high llms.txt score means your file will ingest cleanly when AI engines fetch it, which is a precondition for the AI engine to use your curated link list correctly. It doesn't guarantee citation — content quality and AI-engine model preferences still drive actual citation rates. But a missing or broken llms.txt is a clear citation-blocker for the platforms that respect the standard.