llms.txt
llms.txt is a proposed, publicly accessible text file in a website's root directory that summarises for AI systems, in a simple structured form, which content and subpages are particularly relevant for automated requests.
In practice
Unlike robots.txt, llms.txt does not control technical access; it offers curated orientation for language models. It is a voluntary proposal rather than a standard supported by search engines or AI providers: Google has publicly stated that it does not evaluate the file, and server log analyses show that AI crawlers have barely requested it so far. Anyone publishing it should weigh the effort accordingly – it does no harm, but it is not a proven lever. The load-bearing AEO building blocks remain a clean page structure, clear short answers and structured data.