Glossary
Google-Extended
Google-Extended is a robots.txt token that controls whether a site's content may be used to train Google's Gemini models, without affecting Google Search indexing.
It is a training control, not a visibility control. Disallowing it does not remove a site from Google Search, and does not remove it from AI Overviews, which are generated from the ordinary Search index.
This makes it one of the few clean choices available: a site can decline training use while remaining fully visible in Google's AI-generated answers.
Why it matters
It is widely misunderstood as an AI Overviews opt-out. Treating it as one leads either to a false sense of control or to unnecessary anxiety about visibility.