llms.txt explained: the new file for AI search

Every website has had a `robots.txt` for years — a small text file telling search engines what they can index. Since late 2024 the same concept exists for AIs: `llms.txt`. A short file that tells ChatGPT, Claude, Perplexity and co. where the important content lives.

Most local sites don't have it. The ones that do have a measurable edge in AI citations.

What the file does

Picture an AI crawler hitting your site. Without `llms.txt` it has to click through every sub-page and decide for itself what matters. With `llms.txt` it sees immediately: "Here are the 12 most important URLs of this business, here are the core statements, here are the citable data points."

Two versions exist.

`llms.txt` — the index. A short markdown file with links to the main pages and a one-line description each. Like a sitemap, but for AIs.

`llms-full.txt` — the long form. The most important content as plain markdown text. AI engines can ingest it directly without parsing JavaScript or loading images.

What local businesses put in it

Three blocks should be in `llms.txt`.

One. Who you are, where you are. Name, city, trade, specialisation, years in business, Trustpilot or Google stars.

Two. What you offer. List of services, each with a link to the detail page.

Three. What only you publish. Concrete numbers from your business. Your own cases. Anonymised customer stories. Why original data is the biggest lever for AI citations, here.

What you can do today

Go to your domain plus `/llms.txt` — e.g. `yourbusiness.com/llms.txt`. If you get a 404, you don't have it. That is 90% of local websites today. How we build this in automatically with AI Search setup, here.