Where does an llms.txt file live?

At the root of a domain — for example, arcadelab.ai/llms.txt. Placing it at a predictable path means an AI assistant or a person can find it without guessing.

Is llms.txt an official standard?

It is an emerging convention rather than a formal web standard. It was proposed publicly, documented at llmstxt.org, and adopted by a growing number of sites. There is no governing body enforcing it.

Does adding llms.txt guarantee an AI will read it?

No. It is an offer, not a command. Whether a given assistant fetches and uses the file is up to that assistant. The file simply makes a clear summary available for the ones that do.

What is the difference between llms.txt and a sitemap?

A sitemap lists every URL for crawlers to index. An llms.txt file is a short, human-readable summary of what the site is and which pages matter most. One is a directory; the other is an introduction.

Should every website have one?

It helps most for sites with a clear purpose an assistant might need to explain or act on — a tool, a platform, a documentation set. A file that concisely says what the site is and how to use it is the useful case.

🤖May 15, 2026

What is an llms.txt file?

💡

Quick answer

An llms.txt file is a plain-text file at the root of a website that tells AI assistants what the site is, what it does, and which pages matter most. Think of it as a README written for language models. It is an emerging convention, documented at llmstxt.org, and a site adds one so AI assistants can describe and use it accurately.

AI assistants increasingly read websites on a person's behalf — to answer a question, to explain a tool, to act inside a workflow. An llms.txt file is a website's way of introducing itself clearly to those assistants instead of leaving them to infer everything from raw pages.

What is an llms.txt file?

It is a single plain-text file, placed at a predictable path like /llms.txt, that summarizes a website in language a model can absorb quickly. It is short, structured, and written to be read in one pass. The idea borrows the spirit of robots.txt — a small file at a known location — but its job is explanation rather than crawl rules.

What goes in an llms.txt file?

A short description of what the site is and who it is for
The key URLs, each with a one-line summary
Any rules or formats someone needs to know to use the site
A pointer to a longer document for assistants that want more detail

How is it different from robots.txt?

robots.txt tells crawlers which paths they may and may not visit. It controls access. llms.txt does not control anything — it explains. One is a gate; the other is a guide. A site can, and often does, have both, and they do not overlap in purpose.

Why would a website add one?

When an AI assistant understands a site accurately, it describes that site accurately to the person asking. A clear llms.txt reduces the chance of a wrong summary and makes it more likely the assistant points someone to the right page. For a site whose whole purpose is to be used mid-task, that accuracy is worth a short file.

How does ArcadeLab use llms.txt?

ArcadeLab serves a file at arcadelab.ai/llms.txt that explains the platform, lists the key pages, and describes the publishing format, plus a longer companion document for assistants that want the full briefing. It is part of treating AI assistants as a real audience — the same thinking behind building an AI-friendly website.

Curious what a publishing platform looks like? See arcadelab.ai/publish.

Ready to publish? Paste your HTML file and get a URL.

🚀Publish your thing

What is an llms.txt file?

What goes in an llms.txt file?

How is it different from robots.txt?

Why would a website add one?

How does ArcadeLab use llms.txt?

Related guides