llms.txt is a plain-text file placed at your site root that tells AI engines what your site offers and links to your most important pages. Like robots.txt for crawlers, it acts as a curated map for large language models — helping ChatGPT, Claude, and Perplexity understand and cite your content accurately.
llms.txt is one of the simplest, highest-leverage GEO moves you can make — and most sites still don't have one. This guide covers what it is, why it matters, and exactly how to write one today.
It's a Markdown-formatted text file at your domain root (e.g. yoursite.com/llms.txt) that gives AI engines a curated summary of your site and links to your key pages. Think of it as a friendly map written for large language models rather than search crawlers.
AI engines need to understand your site quickly. A clean llms.txt reduces ambiguity — it states who you are, what you offer, and where the important content lives, improving the odds of accurate citation.
A basic structure looks like this:
# Your Brand> One-line summary of what you do.## Services — followed by links to each service page with a short description.## Contact — phone, email, address.| File | Audience | Purpose |
|---|---|---|
| robots.txt | Crawlers | What they can access |
| llms.txt | AI models | What your site means |
You need both: robots.txt to allow AI crawlers like GPTBot and ClaudeBot, and llms.txt to explain your site to them.
An llms.txt is only useful if crawlers can reach your site. Make sure robots.txt welcomes GPTBot, ClaudeBot, PerplexityBot, and Google-Extended.
Boxfy ships llms.txt and AI-crawler-ready robots.txt on every build through AI SEO, GEO & AEO services and web development.
Boxfy configures llms.txt, robots.txt, and schema so AI engines understand your site.
Get AI-ReadyIt's a widely-adopted community convention rather than a formal W3C standard, but major AI-focused sites use it today to guide model understanding.
At your domain root, so it's reachable at yoursite.com/llms.txt — the same location pattern as robots.txt.
No single file guarantees citations. llms.txt improves comprehension and crawlability, which raises citation probability alongside structure and authority.