llms.txt: what this file changes for your SEO, AI and GEO

The llms.txt file is a proposal by Jeremy Howard, co-founder of Answer.AI, published in 2024 on the llmstxt.org website. The idea: AI reads web pages poorly, as they are cluttered with menus, scripts and ads; a short file, written in Markdown, gives it the essentials of the website and the pages to read.

A second version of the proposal was published on 10 August 2026, after two years of use. It mainly helps agents find the file and the Markdown versions of pages.

The file goes at the root of the website, at yourwebsite.co.uk/llms.txt. It contains, in this order:

• a title, the name of the website or business: it's the only required part;
• a one- or two-sentence summary, presented as a quote;
• if needed, a few paragraphs of details;
• sections, each with a list of links: the page name, its address and a short description;
• by convention, an “Optional” section for secondary pages.

The proposal also recommends publishing a Markdown version of important pages, for example at the same address followed by .md.

According to the project website, thousands of websites publish an llms.txt file, and coding agents use it reliably to read technical documentation. OpenAI, Anthropic and Google publish one for their own developer documentation.

Getting cited in an answer is another matter:

• Google says so in its May 2026 guide: the llms.txt file neither helps nor harms visibility in its results, AI Overviews and AI Mode included;
• OpenAI hasn't published anything indicating that ChatGPT or its crawlers read this file to choose their sources;
• to our knowledge, no major assistant has presented it as a way to get cited.

In short: llms.txt mainly helps agents looking for documentation. For a business that wants to be recommended by ChatGPT or by Google, it replaces neither SEO nor GEO.

One point to remember: llms.txt doesn't block anything. To block or allow an AI crawler, robots.txt is what counts.

• Yes, if your website publishes documentation, an API or a lot of technical content: agents already use it.
• Why not, for a small business: it takes 10 minutes, does no harm, and presents your business in a few clear lines. Do it after the essentials: AI crawlers allowed, pages indexed, pages that answer your customers' questions, structured data, mentions on other websites.
• No, if it comes at the expense of the rest: no file makes up for a missing page or a blocked crawler.

The iasyo audit checks whether the llms.txt file is present and of good quality, with a low weight in the score, precisely because its effect hasn't been demonstrated.

The home page, your service pages or best-selling products, the About page, reviews, contact and your most useful guides. Only public pages that search engines can index.

An example built around a fictitious business:

Save it as plain text, encoded in UTF-8, under the name llms.txt (with an s, not llm.txt), at the root of the website. Check that it opens at yourwebsite.co.uk/llms.txt.

• with Yoast SEO: Settings, Site features, then AI tools, and turn on llms.txt;
• with Rank Math: turn on the LLMS Txt module in the Rank Math dashboard, then configure it in General Settings.

Check the result: the plugin doesn't know which pages matter most to your customers.

Update it with each new important page and each change of address, especially after a redesign.

• listing private pages, pages excluded from search engines or pages blocked in robots.txt;
• thinking it blocks AI: it doesn't block anything;
• stuffing it with keywords: it's a presentation, not a list of words;
• announcing things your pages don't say: AI platforms cross-check their sources;
• letting it go stale after a redesign, with dead links.