llms.txt explained: the small Markdown file that lets an AI understand your website fast, what goes in it and what it is for.
llms.txt is a Markdown text file. It sits at the web path /llms.txt in the root directory of the website. It was proposed in 2024 by Answer.AI so that an AI can understand a website faster.
First you have to understand how an AI works. An AI works with what is called a context. This context is the knowledge the AI has available for a given task.
An example: you ask an AI to do a simple bit of maths. Everything that goes into the answer is the context. And that context is limited.
That is why llms.txt was created. Instead of processing the entire website with heaps of useless data, the AI reads a short, clean summary. That is simpler, faster and fits into the limited context.
Markdown, nothing more. It starts with the company name as a heading, followed by a sentence or two on what it is about. Then come sections with links to the important pages, each with a short description. If you want more, you add an llms-full.txt on top, which holds the complete content.
Think of it like a table of contents, or like a menu: the AI sees at a glance what is there and where it lives.
In short, everything someone should know about you. Who is behind it, what the services are, the most important pages, the blog, contact. No marketing waffle, just clear sentences.
The three get mixed up a lot, but they do completely different jobs:
robots.txt tells search engine crawlers what they may and may not do.sitemap.xml is a list of all the addresses on your website, so search engines miss nothing.llms.txt sums up your content in clear language for AI.The first two are aimed at search engines, the last one at language models.
It is easiest once you see it. This site here has one too: nucez.com/llms.txt. Worth a look — it quickly becomes clear how simple the whole thing is.
Honestly: llms.txt is still young. It is not an official standard from Google or OpenAI, and not every AI reads it automatically yet. But the effort is small, it can do no harm, and whoever is early is ready when it catches on.
llms.txt is the manual for your website, written for AI. It costs little and makes it easy for an AI to understand you correctly.
Why that matters in the bigger picture is in SEO is not enough anymore: now GEO matters too. And if you want to know whether your website is readable for AI, take a look at my SEO and GEO analysis.