A new file has quietly appeared in the toolkit of anyone who wants to be found by AI: llms.txt. It's simple, it's underused, and it's one of the easiest ways to make your business clearer to AI answer engines. Here's what it is and whether you need one.

What llms.txt actually is

llms.txt is a plain-text file placed at the root of your domain (yoursite.com/llms.txt) that describes who you are, what you do, and what your key content is — written in natural language for AI models to read. Where a website is cluttered with navigation, scripts, and styling that an AI has to wade through, llms.txt gives it a clean, direct summary it can parse and use immediately.

How it differs from robots.txt and schema

These three are often confused, but they do different jobs. robots.txt controls which crawlers can access your site — it's about permission. Schema.org markup adds structured, machine-readable data inside your pages — it's about structured facts. llms.txt is natural-language description written specifically for AI to understand your site as a whole — it's about clarity. You want all three; they complement rather than replace each other, as covered in SEO vs AEO.

Do you need one?

If you care whether AI engines describe your business accurately — and increasingly you should — then yes. It's cheap to create, does no harm, and gives AI a clean source of truth about you instead of forcing it to infer from a cluttered site. For personal brands, service businesses, and anyone whose reputation is part of their offering, it's a clear win. It's also a core step in getting cited by ChatGPT.

What to put in it

Keep it clear and factual: who you are, what you do, your key services or products, links to your most important pages with short descriptions, and specific verifiable facts. Write it as if briefing someone who needs to describe your business accurately in one paragraph — because that's exactly what an AI will do with it.