llms.txt
A plain-text file at the root of your site that tells AI models which URLs are worth reading.
Full definition
llms.txt is a community standard (originally proposed by Jeremy Howard) for a Markdown-formatted file served at /llms.txt. It lists the most important URLs on your site — docs, key landing pages, changelogs — with short descriptions so AI models can find the high-signal content quickly without crawling everything.
AI models have limited context windows. When they decide what to ingest from your site, llms.txt is a curated short list that vastly outperforms whatever they'd discover from sitemap.xml alone. Sites with a well-maintained llms.txt get cited disproportionately often.
Example
/llms.txt → # Acme\n\n## Docs\n- [Getting started](https://acme.com/docs/start): 5-minute setup guide\n- [API reference](https://acme.com/docs/api): Full REST API spec
Related terms
Generative Engine Optimization — optimizing for citation by AI chat, search, and assistants.
Answer Engine Optimization — optimizing for direct-answer surfaces like AI assistants and voice search.
Google's AI-generated answers that appear above the classical search results.
OpenAI's web crawler that gathers training data for ChatGPT models.
Put it into practice
Run a free OptimAIze scan to see how your site handles llms.txt and the rest of the GEO checklist.
Run free scanFrequently asked questions
Is llms.txt the same as SEO?
No. llms.txt is one piece of the broader GEO (Generative Engine Optimization) program that sits on top of classical SEO. The two work together — classical SEO gets you crawled and indexed; llms.txt is part of what gets you cited by AI engines.
Do I need a tool to implement llms.txt?
For most teams, a free scanner like OptimAIze is enough to identify what's missing. Implementation is usually a copy-paste of generated markup or a small code change — no specialist tool required.