Does llms.txt work?

01What llms.txt is

llms.txt is a Markdown file at the root of a site, at /llms.txt, proposed by Jeremy Howard in September 2024. The proposal describes it as a way to give AI tools concise background on a site and links to detailed Markdown versions of key pages, because full web pages with navigation, scripts and ads are hard for language models to read within a limited context.

The format is simple: a top heading with the site name, a short summary in a blockquote, optional notes, then sections of links with one-line descriptions. A section called Optional lists links an AI can skip when it needs less context. What is llms.txt? has a short definition.

02What Google says

Google has been direct about this. Its AI features documentation says there are no additional requirements and no special optimization needed to appear in AI Overviews or AI Mode beyond being indexed and eligible for a snippet. Google's Gary Illyes said Google does not support llms.txt and is not planning to, as reported by Search Engine Land, and John Mueller has compared it to the old keywords meta tag, which Google ignores.

So for Google traffic, an llms.txt file changes nothing. The page itself is what gets read.

03Where llms.txt does help

The clearest use is developer documentation. Many documentation sites publish llms.txt and full-text versions so developers can paste one URL into an AI coding assistant and give it accurate context about an API. Some agent and IDE tools look for these files. For a library or SaaS product with docs, that is a real benefit to your users.

For a typical business or marketing site, the benefit is small and speculative. AI assistants that browse in response to a user's question generally fetch and read your actual pages.

04What actually gets you into AI answers

The same things that get you into search results. AI search features retrieve pages from an index and then summarize them, so your pages need to be crawlable, indexed and clearly written. Specifically:

• Allow AI search crawlers in robots.txt; should I block AI crawlers? explains which ones.
• Put the direct answer in the first paragraph under a heading that matches the question.
• Use specific facts, prices, dates and named sources instead of vague claims.
• Render text in HTML so crawlers that do not run JavaScript still see it.
• Earn links and mentions, which help both search engines and AI systems judge trust.
• Add structured data such as schema markup for products, FAQs and articles.

05Should you add one anyway?

If you have documentation, yes: it is useful to the developers using AI tools with your product. If you run a business site, it is optional. It takes a few minutes, costs nothing and does not affect Google, so adding one is a reasonable hedge as long as it does not distract from the work that matters. Keep it accurate; an outdated llms.txt that describes old prices or services is worse than none.

Spend most of your effort on the pages themselves. How to show up in Google AI Overviews and how to make a website AI friendly cover that.