LLMs.txt Checker
Does a domain have an llms.txt? Detect, preview & flag issues.
Enter any domain and we probe for /llms.txt and /llms-full.txt — reporting whether each exists (HTTP 200), its file size, a full preview, and a quick spec check (error & warning counts, link and section totals) on the llms.txt. Fetched through our server so CORS is never a problem. Free and unlimited.
How to use LLMs.txt Checker
Enter the domain
Type any website domain into the free online llms.txt checker — no https:// needed, since the tool normalizes your input to the site origin automatically.
Run the check
Click Check and the tool instantly probes the domain for both /llms.txt and /llms-full.txt through our server, so CORS never blocks the request.
Read the badges
See a clear Found or Not found badge for each file along with its HTTP status, byte size, and content type so you know exactly what the site exposes.
Review the spec summary
For a detected llms.txt, scan the quick spec check showing error and warning counts plus total links, sections, and the parsed site title at a glance.
Check encoding health
Spot mojibake or a missing charset=utf-8 declaration that would garble accented characters, then re-export your llms.txt as UTF-8 to fix it.
Preview, copy or build
Expand the full file preview, copy or open it in one click, or jump to the llms.txt generator to build one when a site has no file yet.
Frequently asked questions
What is an llms.txt checker and what does it do?
An llms.txt checker tells you whether a website exposes an llms.txt file. This free online llms.txt checker probes a domain for /llms.txt and /llms-full.txt, reports whether each exists with its HTTP status and size, previews the contents, and runs a quick spec check on llms.txt.
How do I check if a website has an llms.txt file?
Enter the domain and click Check — the tool fetches the site's /llms.txt and /llms-full.txt through our server (so CORS is not an issue) and shows a Found or Not found badge for each, along with a full preview and a one-click link to open the file.
What is the difference between llms.txt and llms-full.txt?
llms.txt is the concise curated map of your most important pages, while llms-full.txt is an expanded version that can include the full text content for AI models. This checker detects both files at a domain so you can see which ones a site publishes.
Why does the checker say 'no real file' when the URL returns HTTP 200?
Single-page apps answer every unknown path with their HTML app shell at HTTP 200, so /llms.txt only looks like it exists. The checker detects this SPA fallback and flags it; put a real plain-text llms.txt in your public folder or a serverless route so it serves as text/plain.
Does the checker validate the llms.txt against the spec?
Yes. When llms.txt is found it runs a quick spec check and shows error and warning counts plus the number of links and sections and the site title. For a full per-line audit you can use the dedicated llms.txt validator.
Why are accented characters showing as garbled mojibake in my llms.txt?
That usually means the file was saved double-encoded or is served without a charset=utf-8 declaration, so browsers and AI agents misread characters like — ₹ … as sequences such as â€. The checker flags both issues; re-export the file as UTF-8 and serve it as text/plain; charset=utf-8.
Is this llms.txt checker free to use?
Yes, it is free and unlimited. Both files are fetched through our server so you avoid CORS problems, and if a site has no llms.txt yet you can build one with the linked llms.txt generator.
Related tools — AI · LLMs.txt tools
- LLMs.txt Generator — Crawl your site and build a spec-compliant llms.txt for AI.
- LLMs.txt Validator — Check an llms.txt against the llmstxt.org spec.