What Is Google-Extended? Definition and Example

Google-Extended is a product token you can use in robots.txt to manage whether content Google crawls from your site may be used to train future Gemini models and for grounding in Gemini Apps and Vertex AI. Google says it doesn't affect a site's inclusion in Google Search and isn't a ranking signal (Google).

What does Google-Extended control?

According to Google's crawler documentation, it covers:

• Training future generations of Gemini models that power Gemini Apps and the Vertex AI API for Gemini.
• Grounding, meaning providing content from the Google Search index to the model at prompt time, in Gemini Apps and Grounding with Google Search on Vertex AI.

What doesn't it control?

Example

User-agent: Google-Extended
Disallow: /

Illustrative: a news publisher that wants to remain in Search, including AI Overviews, but doesn't want its content used to train Gemini could use this rule. Blocking Googlebot instead would remove it from Search entirely, which is a very different decision.

Is it a crawler?

No. Google says Google-Extended doesn't have a separate HTTP request user agent string; crawling uses existing Google user agents and the token works "in a control capacity". So you won't find it in your logs.

What's changing?

Google's documentation notes it intends to support the AIPREF shared machine-readable training preference signal in early 2027. Check the current page before changing your rules.

Why it matters for GEO

Many teams block Google-Extended believing it protects them from AI Overviews, or avoid it fearing it hurts Search. Neither is right. Decide based on training and Gemini grounding, and manage Search visibility through normal indexing controls.

Related

• Google-Extended: what it controls
• AI crawler
• Grounding