Does llms.txt help AI search visibility?

llms.txt is a proposed convention: a Markdown file at the root of a site that summarises the site and links to its key pages for large language models. It is not an official standard, and publishing one doesn't instruct any crawler to do anything.

Google's generative AI optimization guide says you don't need to create new machine-readable files, AI text files, markup or Markdown to appear in Google Search, including its generative AI features. The crawler documentation published by OpenAI, Anthropic and Perplexity focuses on user agents and robots.txt controls rather than llms.txt.

Where it can still be useful:

• Developer documentation, where coding assistants may read a concise index of your docs.
• As a tidy inventory of the pages you most want AI systems to understand.

Don't treat it as a substitute for what does matter: AI crawlers allowed in robots.txt and at the firewall, content readable without JavaScript, clear and accurate answers on your pages, and consistent facts about your business across the web. Our AI search readiness study deliberately didn't score llms.txt for this reason.