llms.txt, explained: what it is and whether it helps

What llms.txt is

llms.txt is a proposal, first published in 2024 by Jeremy Howard of Answer.AI. It suggests placing a plain-text Markdown file at the root of your website, at /llms.txt, that summarises the site and links to its most useful pages. The idea is that a language model with a limited context window can find the important content without crawling everything.

It is modelled on robots.txt and sitemap.xml in one sense: it is a well-known file at a fixed address. But it is not a standard adopted by search engines. It is a convention that some sites follow. A companion idea, llms-full.txt, puts the full text of the documentation in one file. Both are most common on developer documentation sites.

For a small business, the practical takeaway is simple. The file is optional. It does not replace good page content or being mentioned on sites that assistants already read.

A short example

The file starts with a level-one heading with the site name, an optional blockquote summary, then sections of links with one-line descriptions. For example, a bike shop in Bristol might write a heading 'Pedalworks', a one-line summary 'Bike shop and workshop in Bristol', a section 'Services' linking the servicing and repair pages, and a section 'About' linking the contact page.

Keep it to the pages a customer would ask about: services, prices, locations, contact. Do not list every page. A hand-written file of twenty lines is better than a generated list of five hundred.

Here is the shape in plain terms:

• Heading: the business name
• Summary: one line on what you do and where
• Services: links to the pages that explain what you sell
• About: link to contact and location details

Who actually reads it

Google has said, in its May 2026 guidance on generative AI features, that no machine-readable AI files, Markdown or special markup are needed. Such files get no special treatment in Google Search, which includes AI Overviews and AI Mode. See Google's generative AI guidance.

OpenAI, Anthropic, Perplexity and Microsoft have not published a statement that their assistants fetch llms.txt when answering questions. Some AI tools and coding assistants do read it when a developer points them at a documentation site. That is a different use case from a customer asking for a plumber in your town.

So the honest answer is: it does not hurt, it takes ten minutes, and it is not a visibility strategy. If an agency sells llms.txt as the fix for AI search, ask what else is in the plan. For example, a dentist in Leeds might be told that adding llms.txt will make ChatGPT recommend them. It will not, on its own.

What does move the needle

If you want AI assistants to name your business, focus on four things. None of them is a file. All of them are within reach of a small team.

1. Let the AI crawlers in. Each assistant that searches the web has its own crawler. A block in robots.txt or a firewall rule keeps you out of answers entirely. Vasukai's free robots.txt checker tests 18 AI crawlers at once. See the robots.txt checker.
2. Make the page itself readable. Say what you do, where, for whom, and at what price, in text near the top, with headings and structured data. The free page audit scores this out of 100. See the AI visibility audit.
3. Be mentioned where the assistants already look. That means review sites, directories, comparison articles and forums. See brand mentions in AI search.
4. Then measure. Ask the assistants your customers' questions and read whether you are named. The free check does one round. A plan repeats it on a schedule.

For example, a bakery in Dublin might find that ChatGPT names two competitors but not them. The fix is usually not a new file. It is clearer page copy, a few accurate directory listings, and a review profile that mentions the bakery by name.

Vasukai asks the assistants the questions your customers ask, on a schedule you pick, and shows whether you are named, who is named instead, and which websites the assistants cite. It also gives a ranked list of actions and a 'Write it for me' button that drafts the text for each fix.

If you still want one

Write it by hand in a text editor. Generators exist, but a hand-written file of twenty lines is better than a generated list of five hundred. You know which pages your customers care about.

Put it at the root, serve it as plain text, and keep it current when pages move. Add it to nothing else. It needs no link from your pages and no entry in robots.txt.

Treat it as housekeeping, not marketing. If you have ten minutes and want the file, write it. Then spend the next hour on the four steps above.