What is llms.txt? It's a short file that sums up your website for AI tools. AI agents can read it at your domain root, then follow its links.
You may have heard it pitched as a must-have for AI search. The truth is more modest. This guide explains who reads the file and when it's worth adding.
Reporting note: We checked the llms.txt proposal and Google's documentation on October 5, 2026. These pages change often. This guide can't promise rankings, traffic, or AI citations.
Key takeaways
- llms.txt is a community proposal, not an official standard
- Google Search doesn't use it, and it won't help or hurt rankings
- It doesn't block AI crawlers, so use robots.txt for that
- Chrome's Lighthouse skips the check if you have no file
- Fix crawling, indexing, and clear pages before adding one
What is llms.txt?
The proposal first appeared in September 2024. It's written in Markdown, a simple way to format plain text. The goal is to help AI agents find key pages without wading through messy HTML.
Only one part is required: a top heading with the site's name. Everything else is optional. Most files add a short summary and a few lists of links.
Here's how the parts could look for a fictional plumber. We made up the business and its pages for this example.
Scroll sideways to read the full table.
| Part | Required? | Example line |
|---|---|---|
| Top heading | Yes | # Maple Street Plumbing |
| Short summary | No | > Drain, leak, and water heater repair for homes |
| Extra notes | No | Service area, hours, and how to book |
| Link lists under headings | No | ## Services, then a link to each service page |
| Optional section | No | ## Optional, for pages an agent can skip |
The proposal also suggests clean Markdown copies of key pages. For example, a services page could have a matching.md version. That's extra work, and it's optional too.
Is llms.txt an official standard?
No. Its own site calls it a proposal. Compare that with robots.txt, which the IETF published as RFC 9309 in 2022.
Version 2 of the proposal came out in August 2026. It added standard link tags that help agents find files. One tag points to a page's Markdown copy, and another points to llms.txt.
Version 2 also lets a file in a folder cover just that folder. A help center could use /docs/llms.txt, for example. When two files apply, the more specific one wins.
The proposal's site says thousands of sites publish a file. It also says AI labs publish them for their own developer docs. Publishing a file isn't the same as AI search reading it, though.
Does Google use llms.txt?
Google is clear on this one. Its AI optimization guide says Google Search doesn't use these files. Adding one will neither help nor hurt your visibility or rankings in Search.
Google added that note on June 15, 2026, to answer community questions. The same guide says it's fine to keep a file for other services.
Google's AI features page sets the real bar. A page must be indexed and eligible to show with a snippet. There are no extra requirements for AI Overviews or AI Mode.
Our guide to query fan-out covers what else Google says you can skip. That includes content chunking and special AI markup.
Who reads llms.txt today?
Outside Google Search, the picture is less settled. Version 2 says agents should read the file, then follow the links they need. Whether a given AI tool does that is up to the company behind it.
Here's what public documentation confirms as of October 5, 2026:
- Google Search: doesn't use it, per its AI optimization guide
- Chrome's Lighthouse: checks for it in an experimental agentic browsing category
- AI labs: some publish llms.txt files for their own developer docs
- Other AI tools: check each company's own crawler or agent documentation
Be careful with any claim that a file boosts AI citations. Ask for the official source behind it. If there isn't one, treat the claim as a guess.
How is llms.txt different from robots.txt and a sitemap?
These three files sound alike, but they do different jobs. Google documents both robots.txt and XML sitemaps for Search.
Scroll sideways to read the full table.
| File | What it does | Status |
|---|---|---|
| robots.txt | Tells crawlers which URLs they may crawl | Published as RFC 9309 in 2022 |
| XML sitemap | Lists the pages you want search engines to find | Supported by Google Search |
| llms.txt | Gives AI tools a short guide to key pages | Community proposal, version 2 in August 2026 |
Here's the big point: llms.txt doesn't block anything. It's a guide, not a set of rules. To limit crawling, robots.txt is the tool.
Google also offers a robots.txt token called Google-Extended. It controls whether Google may use your content to train future Gemini models. Google says it doesn't affect inclusion or ranking in Search.
Should a small business add llms.txt?
For most small businesses, it's a low-priority extra. It's cheap to add, and Google says it won't hurt you in Search. But it won't fix problems that keep customers from finding you.
Check these basics before you spend time on it:
- Key pages indexed in Google, confirmed in Search Console
- No stray noindex tags or robots.txt blocks on pages you want found
- Clear service, pricing, and service area pages written for people
- Real buttons, links, and labeled form fields
- Fast pages that work well on phones
Once those are done, adding a file is a fair test. It fits best on sites with lots of documentation, like software help centers. Our AEO audit guide walks through the basic checks that help customers find you.
Our GEO services work on the same order of priorities. We aim to help customers find your business in AI search, starting with the basics.
How to add llms.txt to your website
If you decide to add one, keep it short and honest. These steps work for most small sites.
- Pick the five to ten pages that answer what customers ask most.
- Write a top heading with your business name and a one-line summary.
- Group the links under short headings, like Services and Help.
- Give each link a short note on what the page covers.
- Save the file as llms.txt and upload it to your domain root.
- Open the file in a browser to confirm it loads.
- Update it when you add, move, or remove key pages.
Some site platforms may create the file for you. Check your platform's settings before you write one by hand. List only pages that exist, and describe them accurately.
Chrome's Lighthouse can test the file. Its llms.txt audit flags your page if fetching the file returns a server error. If you have no file, it marks the check not applicable.