Free LLMs.txt Validator & Checker

Check your llms.txt file against the official spec. Get a compliance score, per-check explanations, and specific fix suggestions — free, instant, no login.

Up to 17 validation checksCompliance scoreLine-level highlightsActionable fix tips

We'll look for yoursite.com/llms.txt automatically.

Validation Coverage

What we check — and why it matters

Required

H1 Title

The first line must be a single `# Site Name`. AI models use this as the canonical identity for your site.

Required

Blockquote Summary

A `> One-sentence tagline` immediately after the H1. This is what AI models show when citing your site.

Required

H2 Sections + Links

Each section (## Heading) must contain at least one Markdown link. Empty sections confuse crawlers.

Structure

Description Paragraph

Plain text after the blockquote gives AI models narrative context about your audience and value prop.

Quality

Link Format

Links must follow `- [Title](url)` Markdown syntax. Malformed links are ignored by AI crawlers.

Quality

HTTPS Links Only

HTTP links may redirect or fail. AI crawlers expect clean canonical HTTPS URLs.

Quality

No Duplicate URLs

The same URL listed twice dilutes signal. Each page should appear exactly once.

Quality

No Query Strings

UTM parameters and other query strings create URL fragmentation. Use clean canonical paths.

Hygiene

File Size ≤ 10KB

The recommended ceiling. Larger files may be truncated or skipped entirely by AI crawlers.

Hygiene

10–50 Links

Too few links under-represent your site. Too many dilute attention. 10–50 is the goldilocks zone.

Hygiene

UTF-8 Encoding

The file must be UTF-8 encoded without a BOM. A BOM prefix can break parsers that read the file.

Live Check

AI Crawler Access

We send real HEAD requests as GPTBot, ClaudeBot, PerplexityBot, and Meta-ExternalAgent to verify none are blocked by your server or WAF.

Live Check

robots.txt Conflict

We fetch and parse your robots.txt to check if any AI crawlers are disallowed from / or /llms.txt — a valid file is useless if crawlers are blocked at the door.

Live Check

Dead Links

We HEAD-request every URL listed in your llms.txt (up to 20) to find 404s, timeouts, and broken pages before AI crawlers do.

Conditional

llms-full.txt Exists

If your file references an llms-full.txt URL, we verify the file actually exists and is reachable — many sites reference it but never create it.

How the compliance score works

Each check is weighted by importance. Critical structural checks count more than best-practice checks.

85–100
Excellent
Fully optimized
65–84
Good
Spec compliant
40–64
Fair
Needs work
0–39
Poor
Missing essentials

Frequently asked questions

Want AI to recommend your brand?

A valid llms.txt is step one. Let RankSaver help you build full AI search visibility — tracked, measured, and growing.

Get a Free Visibility Audit
Free Visibility AuditBook a Call