Search engines have robots.txt and the sitemap. Language models now have a proposal of their own: llms.txt. It is a Markdown file, placed at yoursite.com/llms.txt, that introduces the site in a few lines and points to the pages that matter.
The idea was put forward in 2024 by Jeremy Howard of Answer.AI. It starts from a simple observation: a modern web page is full of menus, scripts and banners. A model reading it wastes its attention on noise. A clean summary helps it get straight to the point.
What the file looks like
The format is deliberately minimal. A title, a one-sentence summary, then lists of annotated links, grouped into sections.
- A title line with the name of the business or site.
- A quote (a line starting with >) that says in one sentence what you do and for whom.
- A few sections (Services, Guides, About) with links and a short description of each.
- An optional section for secondary pages that a model can skip if it runs out of room.
What it does, and what it doesn't
Let's be honest: to date, none of the major assistants has publicly confirmed that it reads llms.txt to build its answers. The file won't put you in ChatGPT overnight.
It is still useful for three reasons. Developer tools and agents already use it, for example to read technical documentation. It forces you to write, in one clear sentence, what your business does, and that sentence is useful everywhere else. And it costs almost nothing: twenty minutes, once.
Write yours in 20 minutes
Start with the summary sentence. If you can't say what you do in one line, that's a sign your home page has the same problem, and that AI also struggles to describe you.
Then list five to fifteen pages, no more: the ones that answer the questions your customers ask. For each one, a factual description, no slogan. Put the file at the root of the site and check that it opens in a browser.
An example to look at
GEOQuébec publishes its own at /llms.txt. It is generated automatically from the site's content, which keeps it from going stale. If your site is built with a modern tool, ask your technical team to do the same.