llms.txt Checker
Enter any domain to instantly check whether it has a valid, publicly accessible llms.txt file. No account needed.
What does this checker test?
This tool checks two things: whether your llms.txt file exists at the standard location (yourdomain.com/llms.txt), and whether it returns HTTP 200 — meaning it is publicly readable without authentication.
AI crawlers like ClaudeBot, PerplexityBot, and other AI-powered search systems look for this file when indexing your site. If the file is missing or blocked, these systems have no structured information about your content.
Why llms.txt accessibility matters
- 01AI search engines like Perplexity cite sources directly. A readable
llms.txtincreases your chance of being cited. - 02Anthropic's Claude respects
llms.txtsignals when developers use Claude to process external content. - 03A file that returns 403, 404, or redirects to a login page is the same as no file — AI systems skip it entirely.
- 04Sites in our directory with accessible
llms.txtfiles consistently report better AI-driven referral traffic.
How to fix a failing check
If your domain fails, here are the most common causes and fixes:
- File doesn't exist — create a plain text file named
llms.txtand upload it to your site root. - Wrong path — the file must be at
yourdomain.com/llms.txt, not a subdirectory. - Blocked by robots.txt — check that your robots.txt does not
Disallow: /llms.txt. - Authentication required — the file must be publicly readable with no login, cookie, or token.
- Server error — if your server returns 500 or similar, check your hosting configuration.
Need help creating the file? Read our step-by-step implementation guide →
Frequently Asked Questions
What does this llms.txt checker do?
It checks whether your website has an llms.txt file at the standard location (yourdomain.com/llms.txt) and whether that file is publicly accessible — returning HTTP 200. It does not validate the file content, only its existence and accessibility.
What does it mean if my llms.txt is not accessible?
If the checker returns a failure, it means AI systems like ChatGPT, Claude, and Perplexity cannot read your llms.txt. Common causes: the file doesn't exist, it's blocked by authentication, or your server returns a redirect or error for that path.
How do I fix a failing llms.txt check?
Create a plain text file named llms.txt and place it in your website root directory so it's reachable at yourdomain.com/llms.txt with no login required. Check your robots.txt is not blocking the path. See our implementation guide for step-by-step instructions.
Does llms.txt need to be at the root of my domain?
Yes. The llms.txt standard requires the file to be at the root of your domain: yourdomain.com/llms.txt. Subpaths like /blog/llms.txt are not recognized by AI crawlers.
What is the difference between llms.txt and llms-full.txt?
llms.txt is a concise overview of your site (recommended under 2,000 tokens). llms-full.txt is an optional extended version with comprehensive content, detailed API docs, or full page exports. AI systems typically read llms.txt first.
Which AI systems read llms.txt?
AI systems that read llms.txt include Anthropic Claude (ClaudeBot), Perplexity AI (PerplexityBot), and developer tools that use the llms.txt standard for context. OpenAI's GPTBot crawls sites independently but the llms.txt standard helps structure what they find.
Your llms.txt is accessible?
Submit your site to our directory and get listed alongside 1,478+ AI-ready websites.