llms.txt is a Markdown file at the root of a website that gives AI tools a short, curated guide to its most useful pages. Jeremy Howard of Answer.AI proposed it on 3 September 2024, and the proposal was revised in August 2026. It's easy to add and does no harm, but it doesn't control crawling, and Google has said Search ignores it.
What the file looks like
- An H1 with the name of the site or project. This is the only required part.
- A blockquote with a one or two sentence summary.
- Optional paragraphs of context.
- H2 sections containing Markdown links, each with a short description.
- Optionally, a section named "Optional" for pages that can be skipped when space is short.
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- [Pricing](https://automatedseo.app/pricing): one plan, $99 a month per website, 30 articles a month
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## Free tools
- [llms.txt generator](https://automatedseo.app/tools/llms-txt-generator): generate an llms.txt file from your sitemapWho reads it
| Reader | What it does with llms.txt |
|---|---|
| Google Search, including its AI features | Ignores it. Google says the file neither helps nor harms visibility. |
| Chrome Lighthouse | Runs an llms.txt audit that only flags server errors when fetching the file. It doesn't affect any score, and a missing file counts as not applicable. |
| AI coding assistants and agents | Read it when a person or tool points them at it, which was its original purpose: documentation for AI tools. |
| ChatGPT, Claude and Perplexity | No public commitment either way. |
What it does
It gives any tool that reads it a clean summary of your site without navigation, scripts or ads in the way. That's useful for AI coding assistants reading documentation and for agents that are told to look for it, and it forces you to decide which pages actually explain your business.
What it doesn't do
- It doesn't block or allow crawlers. That's robots.txt: see which AI crawlers to allow.
- It doesn't replace your sitemap. Crawlers still discover pages through sitemaps and links.
- It isn't a guarantee that ChatGPT, Claude, Gemini or Perplexity will read it, or cite pages because they're listed.
What about llms-full.txt?
Some documentation platforms also generate llms-full.txt, a single file holding the full text of every page. It isn't part of the proposal. The proposal instead suggests offering a clean Markdown version of individual pages at the same URL with .md appended.
Should you add one?
Yes, if it takes you less than an hour. Keep it short, keep it current, and serve it as plain text at /llms.txt. Our free llms.txt generator builds a first draft from your sitemap. Then spend the rest of your effort on what assistants demonstrably use: crawlable pages with clear, quotable answers. It's one small part of generative engine optimization, and our AI visibility checks look for it without treating it as essential.
Those clear, quotable pages are the part that takes real time, because you need a steady supply of them, not one. A tidy llms.txt pointing at five pages won't win the questions your buyers ask about the other fifty. AutomatedSEO writes and publishes 30 a month to your site, each one researched against what already ranks, written in your voice, answer-first and with its sources linked.
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Sources
Checked on 27 September 2026.
Written by
Founder and SEO enthusiast
Mielad Niekzad is the founder of AutomatedSEO and an SEO enthusiast.
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