llms.txt: What It Is and Whether It Actually Works

llms.txt

llms.txt is a plain-text file at the root of a domain that tells large language models which pages matter and how to read them, in the way robots.txt speaks to crawlers. It is a proposed convention rather than a standard, and Google Search does not use it.

Last reviewed 17 September 2026

What the file contains

A short description of the site, then a curated list of the URLs worth reading, usually grouped with a line of context each. The point is to hand a model a clean map instead of making it infer structure from navigation and internal links.

Some sites also publish llms-full.txt, which inlines the actual content of those pages as markdown so a model can read the substance without fetching anything.

llms.txt against the files that do have standards
	robots.txt	sitemap.xml	llms.txt
Status	Long-standing standard	Long-standing standard	Proposed convention
Used by Google	Yes	Yes	No
Controls	Crawler access	Discovery of URLs	Nothing, it advises
Worth publishing	Essential	Essential	Cheap, unproven

Be honest about what it does

Adoption is genuinely unclear. No major search engine has confirmed it as a ranking or citation input, and Google has said publicly that Search does not use it. Treating it as a lever that lifts AI visibility on its own is not supported by evidence.

It is cheap to publish and does no harm, which is a reasonable argument for doing it. It is not a reason to bill it as a deliverable that moves citations.

What actually drives citation

Letting the AI crawlers reach your pages at all, which robots.txt does control
Server-rendered HTML, since content behind client-side JavaScript may never be read
Passage structure that survives extraction
Third-party mentions, which weigh more than anything on your own domain

Why it matters for B2B marketing teams

We mention this one mainly to save you money. If an agency proposes llms.txt as a deliverable that will lift your AI visibility, ask for the evidence. It takes ten minutes to publish, which makes it a fine housekeeping task and a poor line item.

Frequently asked questions

Does llms.txt improve AI visibility?+

There is no published evidence that it does. No major engine has confirmed using it, and Google has stated Search does not. Publish it if you like, but the levers that demonstrably matter are crawler access, server-side rendering, passage structure, and third-party mentions.

Where does llms.txt go?+

At the root of the domain, served as plain text at /llms.txt, the same convention robots.txt follows. On Webflow you can host it as a custom root file; on most frameworks it goes in the public directory.