llms.txt Checker

Check whether a site publishes a valid llms.txt — the emerging convention that gives LLMs and AI assistants a curated, plain-text map of your most useful pages.

What is llms.txt?

llms.txt (proposed at llmstxt.org) is a markdown file served at /llms.txt. It gives language-model tools a short description of your site plus curated links to the pages that matter, so an assistant with a limited context window reads your best content first — instead of crawling navigation menus and cookie banners.

Honest note: Google has stated that Google Search ignores llms.txt— it does not improve your Google rankings. Publish it for broader LLM tools, AI assistants and documentation consumers, and treat classic SEO as the way to appear in Google’s AI features.

What this checker tests

Availability — does /llms.txt return HTTP 200 (and does the optional /llms-full.txt exist)?
Content type — is it served as plain text/markdown, or is a SPA catch-all returning HTML?
Structure — H1 title, one-line summary blockquote, H2 sections with link lists, per the llmstxt.org proposal.
Link health — a sample of listed links is fetched to catch dead URLs.
Substance — flags stub files that technically exist but help nobody.

A valid llms.txt example

# Example Co

> Example Co builds widgets for plumbers in Manchester.

## Docs

- [Getting started](https://example.com/docs/start): setup in 5 minutes
- [API reference](https://example.com/docs/api): endpoints and auth

## Policies

- [Pricing](https://example.com/pricing): plans and limits
- [Contact](https://example.com/contact)

Common problems and fixes

The URL returns your homepage HTML

Single-page apps and some CMS setups route unknown paths to the app shell, so /llms.txt “exists” but serves HTML. Fix: serve the file statically (e.g. from public/) with content-type: text/plain and exclude it from catch-all routes.

File exists but is a stub

One heading and a single link helps nobody. Curate the pages you would show a new customer or integrator: docs entry points, pricing, contact, key guides — each with a one-line description.

Links rot after a redesign

llms.txt is easy to forget when URLs change. Re-run this check after any restructure, or set up monitoring so you are alerted when the file breaks.

FAQ

Does llms.txt improve my Google rankings?

No. Google explicitly ignores llms.txt in Search. It is aimed at other LLM tools and assistants that adopt the convention. For Google’s AI features, ordinary technical SEO and high-quality content are what count.

Where must the file live?

At the root of your host: https://example.com/llms.txt. The optional expanded version lives at /llms-full.txt.

What format does it use?

Plain markdown: an H1 with the site name, a blockquote summary, then H2 sections containing bullet lists of links, optionally with a one-line description after a colon.

Is llms.txt the same as robots.txt?

No — robots.txt tells crawlers what they may fetch; llms.txt suggests what is most worth reading. They complement each other and this toolbox will check both.

Related tools

llms.txt Generator — no llms.txt yet? Generate a draft from your sitemap in seconds.

Coming next: AI Readiness Checker, robots.txt Checker, sitemap Checker, DNS Lookup and SSL Checker.

Last reviewed: 2026-07-09. Checks follow the llmstxt.org proposal and Google Search Central guidance current at that date.

Frequently asked questions

▸ What is llms.txt?

A Markdown file at your site root that points AI systems at your most important pages — like a curated, AI-focused sitemap.

▸ What does the checker validate?

The file's structure, its content type, and whether the links it lists are healthy.