llms.txt Validator:
Is Your Site AI-Crawler Ready?
Validate your llms.txt file against the official spec, get an AI-readiness score out of 100, and see a prioritized list of exactly what to fix — in seconds.
The New Standard for Telling AI What Your Website Is About
llms.txt is a plain-text file placed at the root of your domain (e.g., example.com/llms.txt) that communicates your brand, key pages, and allowed content directly to AI language models and crawlers.
Proposed by Answer.AI in 2024, llms.txt is rapidly being adopted by AI crawlers including Perplexity, Claude.ai, and emerging AI search agents. Sites without a well-formed llms.txt give AI systems less context — which means fewer citations and less visibility in AI-generated answers.
Instant Validation in Three Steps
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Enter Your Domain
Type your domain (no need for the full path). Citerank automatically fetches your live llms.txt from the standard location.
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Spec & Readiness Analysis
The validator checks your file against the official llms.txt specification — title, description, sections, linked URLs, word count — and scores AI-readiness on 8 weighted signals.
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Get Your Grade and Fix List
Receive a letter grade (A+ to F), a score out of 100, and a ranked list of specific fixes with copy-paste examples — so you know exactly what to improve.
8 AI-Readiness Signals Scored
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Brand Title
The # heading must be present and contain your brand name. Missing titles cost 25 spec points — it is the most common critical error.
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Description Block
A > blockquote description below the title helps AI systems understand what you do and who you serve before crawling any pages.
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Structured Sections
Validates the presence of ## sections. Three or more well-named sections (About, Services, Resources) maximize AI parsing accuracy.
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Linked URLs
Counts internal URLs in sections. Five or more linked pages let AI crawlers follow your most important content for citation context.
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Content Depth
Checks total word count. Files under 50 words give AI too little context; 200+ words achieves a full readiness score on this signal.
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Artifact Detection
Catches common AI-generation artifacts — code fences, extra markdown — that break llms.txt parsers and reduce citation confidence.
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Section Diversity
Checks whether sections cover key categories: About/Overview, content/resources, and contact. Diverse sections improve AI context.
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HTTP Accessibility
Verifies that the file is publicly accessible at the standard URL path with a 200 OK status — a file that returns 404 is never read by AI crawlers.
Frequently Asked Questions About llms.txt
What is llms.txt?
llms.txt is a plain-text file placed at the root of a website (e.g., example.com/llms.txt) that tells AI language models and crawlers what your site is about, which pages are most important, and what content AI is permitted to use. It was proposed by Answer.AI in 2024 and functions similarly to robots.txt — but for AI systems rather than traditional search crawlers.
How do I validate my llms.txt file?
Enter your domain in Citerank's llms.txt Validator. The tool fetches your live llms.txt, checks it against the official specification, and scores it on 8 AI-readiness signals. You get a letter grade (A+ to F), a list of issues ranked by severity, and specific fix instructions with copy-paste examples.
What does a good llms.txt file look like?
A well-formed llms.txt has: (1) a top-level # Title with your brand name, (2) a > description paragraph, (3) at least 3 structured ## sections (e.g., About, Services, Resources), (4) 5 or more linked URLs so AI can crawl key pages, and (5) at least 200 words of descriptive text. Missing any of these elements reduces the chance that AI systems will cite your content.
Does llms.txt guarantee AI citations?
No — llms.txt is one signal among many. AI systems also consider page content quality, E-E-A-T, structured data, and topical authority. However, sites without llms.txt give AI crawlers less context about what to index and cite, which is a growing competitive disadvantage as AI search becomes mainstream.
What errors does the validator catch?
The validator catches critical errors (no title, no sections, no URLs), high-severity issues (no description block, markdown code fence artifacts), and warnings (empty sections, thin content, sections without URLs). Each issue includes a severity level and an exact fix instruction.