llms.txt is a plain-text file placed at the root of a website (yoursite.com/llms.txt) that presents the essentials of a business in a format designed to be read by large language models — LLMs, the technology behind ChatGPT, Claude or Gemini. Proposed in late 2024 by Jeremy Howard (Answer.AI), the standard starts from a simple observation: AIs read the web, but a modern website is cluttered with menus, scripts and banners that drown the useful information. llms.txt offers them the opposite — a clean summary, in Markdown: who the business is, what it offers, its important pages, how to get in touch.
For a local business, it's the digital equivalent of handing AIs a business card. This site's own file, lucaperrin.com/llms.txt, lists the three areas of expertise, the pricing, the portfolio with testimonials, and every blog article — in French and in English. An AI that needs to answer "what does Luca Perrin do and how much does it cost?" finds everything there, with no risk of misreading a dropdown menu.
Let's be honest about its status, because this is where many providers oversell: llms.txt is an emerging standard, not a guarantee. No major AI provider has officially announced systematic support, and adoption is still debated. So why do it? Because the cost is near zero, the risk is zero, and the potential upside is real: some tools and agents already read it, and the exercise forces you to clarify your business information anyway — which also benefits your structured data and your content. It is the textbook asymmetric bet.
Good practices if you create one: stay factual and current (an llms.txt that contradicts the site does more harm than good), write in full sentences rather than keywords, date sensitive information such as prices, and maintain it in every language of the site. llms.txt ships as standard with every website I build — it's basic search hygiene done properly, not a paid option.
Common mistakes
- Treating it as a ranking factor : no major AI engine reliably follows llms.txt today. It's a clarity best practice, not a shortcut.
- Letting it go stale : an llms.txt that contradicts your site content does more harm than good.
- Neglecting the rest : an llms.txt never makes up for a slow, poorly structured site with no structured data.