Where it comes from
The format was proposed in 2024 as a way to give language models a clean summary of a site, without menus, scripts and cookie banners. It is a proposal, not a standard that search engines have adopted.
Developer tools use it most: coding assistants read llms.txt files to find documentation. For being named in AI answers, the evidence is thin. Google’s guidance says the file is not needed for its search or AI features.
What it does not do
It does not let crawlers in or keep them out. That is robots.txt. It does not replace structured data, and it does not make an engine trust you. If AI crawlers cannot fetch your pages, an llms.txt file changes nothing.
How to write one in an hour
Start with a heading with your company name, then one sentence that says what you do, for whom and where. Then a short list of your key pages, each as a Markdown link with one line of explanation: services, prices, how you work, contact. Add your answers to the questions buyers ask most.
Keep it factual and keep it the same as your site. A file that says something your pages do not will only confuse. Ours is at tobefound.xyz/llms.txt: who we are, our services and prices, our answers to common questions, and links to the other languages.
What to do first instead
Let the AI crawlers in, make your key pages readable without JavaScript, describe your company in structured data and make your details the same everywhere. The free check tests these on your own site; llms.txt is a sensible last step.