Does any AI provider read llms.txt?

What llms.txt is

A proposal, published by Jeremy Howard on 3 Sep 2024, for a plain-text file at /llms.txt that summarises a site for large language models. [1][1] llms.txt proposal, https://llmstxt.org/. Proposed by Jeremy Howard, 3 Sep 2024. Opened 23 Oct 2026. It is a proposal, not a standard any search engine or AI provider has adopted for ranking or citing.

What Google says

Google's guide to its generative AI features is explicit: "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 capabilities), as Google Search itself doesn't use them." It adds: "Doing so will neither harm nor help your site's visibility or rankings in Google Search, as Google Search ignores them." [2][2] Google Search Central, "Optimizing your website for generative AI features on Google Search", https://developers.google.com/search/docs/fundamentals/ai-optimization-guide. Last updated 10 Jul 2026. Opened 23 Oct 2026. Google's changelog records the clarification on 15 Jun 2026. [3][3] Google Search Central, "Latest Google Search documentation updates", https://developers.google.com/search/updates. Entry of 15 Jun 2026: "Clarifying guidance on llms.txt files." Opened 23 Oct 2026.

One caveat: Chrome's Lighthouse has an experimental llms.txt check in its agentic browsing category, for AI agents using a browser. A missing file is graded "Not applicable". [7][7] Chrome for Developers, Lighthouse agentic browsing audit "llms.txt", https://developer.chrome.com/docs/lighthouse/agentic-browsing/llms-txt. Last updated 5 May 2026. Opened 23 Oct 2026. That is a browser-agent check, not Google Search.

What the other providers say

• OpenAI. Its crawler page describes GPTBot, OAI-SearchBot and ChatGPT-User, all controlled through robots.txt. It mentions llms.txt only as an index of OpenAI's own documentation, not as something its crawlers read. [4][4] OpenAI, "Overview of OpenAI Crawlers", https://developers.openai.com/api/docs/bots. Opened 23 Oct 2026.
• Anthropic. Its crawler article covers ClaudeBot, Claude-User and Claude-SearchBot, again through robots.txt, and doesn't mention llms.txt. [5][5] Anthropic, "Does Anthropic crawl data from the web, and how can site owners block the crawler?", https://support.claude.com/en/articles/8896518. Updated 7 Apr 2026. Opened 23 Oct 2026. Anthropic publishes an llms.txt for its own docs; publishing one says nothing about reading anyone else's.
• Perplexity. Its bots page mentions llms.txt only as its own documentation index. [6][6] Perplexity, "Perplexity Crawlers", https://docs.perplexity.ai/guides/bots. Opened 23 Oct 2026.
• Microsoft (Bing, Copilot). I found no statement either way.

What that means

• Known: Google Search ignores llms.txt.
• Not known: whether any other provider uses it. None has said so, and none has said it doesn't.
• What does affect being cited: letting the crawlers in through robots.txt, being indexed, and pages specific enough to be worth citing. How to get cited in ChatGPT and AI Overviews.

If you already have an llms.txt, there's no reason to remove it. If someone is selling you one as an AI visibility fix, ask them which provider documents reading it.