John Mueller: no AI system currently uses llms.txt
Replying to a question on Bluesky, Google’s John Mueller wrote: “FWIW no AI system currently uses llms.txt.”
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What happened?
On 17 June 2025, replying to another user on Bluesky, John Mueller of Google wrote: “FWIW no AI system currently uses llms.txt.” Search Engine Roundtable reported it the next day.
Is it still true?
It was an informal remark by one Google employee, not company guidance. What has changed since is mostly on the tool side: Google’s Lighthouse added an llms.txt check in May 2026, and research in August 2026 showed AI coding agents looking for llms.txt on their own. On the crawler side, none of Google, OpenAI, Anthropic or Perplexity says in its crawler documentation that it reads other sites’ llms.txt files (checked 17 October 2026).
What does it mean for your site?
Don’t publish llms.txt expecting AI search engines to read it. The readers that do exist are mostly developer tools working with documentation.
Sources
Source: John Mueller on Bluesky
Coverage: Search Engine Roundtable, 18 June 2025