What is llms.txt?

Published: May 9, 2026

llms.txt is a plain-text file you place at your site root that tells AI assistants what your site is about. Think of it as a cover page for AI crawlers: instead of making them parse your full HTML, you give them a clean summary they can read in one shot.

Why it exists

Web pages are built for humans. They have navigation, styling, popups, and JavaScript that AI models have to parse through to find the actual content. For a site that wants AI assistants to describe it accurately, that is a lot of noise.

llms.txt cuts through that. It is structured markdown with your site name, a one-line tagline, a brief overview, and links to important pages. AI crawlers check for it first. If it exists, they use it.

What it looks like

# Your Site Name

> One-line description of what you do

Brief overview paragraph. What problem you solve, who you serve.

## Products / Features

- **Feature 1**: What it does
- **Feature 2**: What it does

## Key Information

- **Website**: https://yoursite.com
- **Pricing**: Free / Paid / Freemium
- **Category**: Developer Tools

## Links

- [Homepage](https://yoursite.com/)
- [Pricing](https://yoursite.com/pricing)
- [Documentation](https://yoursite.com/docs)

The format rules

• Place it at https://yoursite.com/llms.txt — the root only. Subdirectory paths are not checked.
• Use the # heading for your site name and > for the tagline. These are the two fields AI systems use most.
• Keep it under 500 words. Longer files get truncated or ignored.
• Write the description in plain, factual language. Not marketing copy. AI systems cite this text directly, so "we help businesses grow" is worse than "project management software for engineering teams."

How AI assistants use it

• Discovery: when a user asks about your industry or product type, AI crawlers fetch llms.txt to understand if your site is relevant
• Citation: the name and description fields appear directly in AI responses and recommendations
• Context: agents use it to decide whether your service matches a user request before calling your API or visiting more pages

Who should have one

Any site that wants AI assistants to describe it accurately. Local businesses, SaaS products, content sites, developer tools, portfolios, API providers. If an AI might ever need to explain what you do, llms.txt is how you control that answer.

Best practices

• Update it when your product changes. AI cites what it finds.
• Include your pricing model — "is this free?" is one of the most common questions AI gets about tools
• Link to your most important pages, not just the homepage
• Match the description to what actually appears on your site — inconsistency lowers AI confidence in your content