Today’s MarketingBig AI firms back one robots txt rule to opt out of AI training
Google, Microsoft and OpenAI said on October 30, 2026 they will honor one robots.txt policy token, User-Agent: __usage_ai-training, that tells every participating provider not to train AI on a site. An Anthropic engineer told the IETF AIPREF group the same day that Anthropic has started building support. Microsoft starts on February 1, 2027 and Google plans early 2027. Rankings in Google and Bing search are not affected.
Our take
This turns AI training into a one line choice, so make it on purpose instead of by default. Blocking training is not the same as blocking AI answers, and at Google this token will also keep you out of Gemini answers that cite pages. Brands usually want to be cited, so keep your public pages open and block only gated or paid content.
