llms.txt is a plain-text file at yoursite.com/llms.txt that lists your most useful pages for AI tools. It is a proposal, not a standard, and no major AI search engine has said it uses the file to pick sources. This page tells you honestly where it ranks on your to-do list, then helps you write and check a valid file in a few minutes.
Where to start
Decide where llms.txt sits on your list
Here is what has been published. Google says Google Search and its AI features do not use llms.txt, and that the file will neither help nor harm you there (Search Central note, 15 June 2026). OpenAI and Perplexity tell site owners to allow their search crawlers, OAI-SearchBot and PerplexityBot, in robots.txt. Neither crawler page mentions llms.txt. The proposal's author says the file is used most for software docs, where coding agents follow it to the right reference page.
So the file helps an agent that is already on your site find the right page. It does not decide which brands an answer recommends. Answer five quick questions and you get your real order of work.
"Should I bother?" priority check
Runs in your browser. Nothing is sent anywhere. Pick one answer per question; your list updates as you go.
Generate a valid llms.txt from your best pages
The format from llmstxt.org (version 2, August 2026) is short. One # heading with your name is the only required part. Then a one or two sentence summary on a line starting with >, optional plain notes, and ## sections that each hold a list of links: - [Name](https://url): optional note. A section called ## Optional holds links an AI tool can skip when it is short on space.
Pick 5 to 20 pages a shopping assistant would need: main collections, buying guides, size or shade charts, shipping, returns, contact. List only pages that exist.
llms.txt generator Example brand
Runs in your browser. Nothing is sent anywhere. Write one link per line as Name | /path or full URL | note. Start each group with a ## Heading line.
Publish it on your platform
Check the file against the format
Open yoursite.com/llms.txt, select all, copy, and paste it below. The checker tests the parts of the llmstxt.org format that break most often, plus two common mistakes: a normal web page served at that address, and untouched platform defaults.
llms.txt checker
Runs in your browser. Nothing is sent anywhere. The example below has several common mistakes; press Check to see them.
Questions
Does llms.txt help SEO or Google AI Overviews?
No. Google's AI optimization guide says Google Search does not use llms.txt or other machine-readable AI files, and that keeping one for other services neither helps nor harms your rankings.
Is llms.txt the same as robots.txt?
No. robots.txt is a web standard (RFC 9309) that allows or blocks crawlers. llms.txt is a suggestion list and cannot block anything. If robots.txt blocks OAI-SearchBot, a perfect llms.txt will not get you into ChatGPT search answers.
My Shopify store already has one. Should I replace it?
Eventually. The default describes how agents can search and check out, and says little about your products or best pages. Replacing it is low effort, but do it after your crawler access and buying-question pages are sorted.
Who does read llms.txt today?
Some AI agents and coding tools, according to the proposal, and Chrome Lighthouse checks it in its "agentic browsing" audits. Lighthouse flags a server error on the file and marks a missing file as not applicable. It does not score rankings.
Can I put it somewhere other than the root?
Version 2 of the proposal allows a file at a subpath such as /docs/llms.txt, covering the pages under it. For a store, the root is the place agents will look first.
Format: llmstxt.org, v2, 10 Aug 2026. Google AI optimization guide, Search Central update 15 Jun 2026. OpenAI and Perplexity crawler docs, checked Sep 2026. Free guide by SEO to GEO HQ.