Glossary · AI search
llms.txt
Definition. llms.txt is a proposed markdown file at the root of a domain listing the pages an AI system should read to understand the site. It is a curation signal rather than an access control, and adoption by the major AI crawlers remains minimal.
No major engine has confirmed that it uses the file for retrieval, and crawler-log studies show negligible requests for it. That does not make it harmful, only low priority.
The narrow case where it plausibly helps is documentation-heavy software, where a curated index of canonical pages is genuinely more useful than a sitemap.
It is not a substitute for being crawlable, structured and cited elsewhere, which is what actually drives AI visibility today.
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More in AI search: AI SEO · Generative engine optimization (GEO) · Answer engine optimization (AEO) · AI Overview · Zero-click search · LLM visibility · Prompt tracking · Citation (AI)
Frequently asked questions
What does llms.txt mean?
llms.txt is a proposed markdown file at the root of a domain listing the pages an AI system should read to understand the site. It is a curation signal rather than an access control, and adoption by the major AI crawlers remains minimal.
Why does llms.txt matter for AI SEO?
No major engine has confirmed that it uses the file for retrieval, and crawler-log studies show negligible requests for it. That does not make it harmful, only low priority.
What is the most common mistake with llms.txt?
It is not a substitute for being crawlable, structured and cited elsewhere, which is what actually drives AI visibility today.
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