Optimus Pass
Home/Glossary/llms.txt
Crawlers & Structure

llms.txt

Optimus Pass Glossary · Last updated August 29, 2026

Definition

llms.txt is a proposed plain-text file, introduced by Jeremy Howard in September 2024, that gives large language models a curated markdown overview of a website's most important pages. It is designed to complement robots.txt and sitemap.xml — pointing models to the content that matters — not to replace them.

Why it matters

It is an emerging convention, not a standard: no major search engine has confirmed using it for rankings or citations. It is cheap to add and signals AI-readiness, but it cannot substitute for crawlable, well-structured content.

Practical example

A documentation site adds /llms.txt listing its core guides with one-line summaries, so a model fetching the site gets a map of the content instead of raw HTML.

Frequently asked questions

Is llms.txt required for AI visibility?+
No. It is a community proposal with voluntary adoption. Crawlable content, clear structure, and an accessible robots.txt remain the baseline.
Does Google use llms.txt?+
Google has not documented using llms.txt for Search or its AI features. Treat it as an optional convenience for AI agents, not a ranking signal.

Try it with Optimus Pass

Run a Visibility Audit on your site and see how it scores on the checks behind this term.

Visibility Audit

Browse the full glossary for more definitions.

All glossary terms →