Google-Extended

What it does

Google-Extended doesn't send its own requests; instead, it is a standalone token publishers add to robots.txt to control a specific use of content Google's existing crawlers already gather. Setting a Google-Extended rule tells Google whether that crawled content may be used to train future Gemini models or to ground Gemini's answers with up to date information, separate from how that same content is used for Google Search. Google states clearly that Google-Extended has no impact on a site's inclusion in Google Search and is not used as a ranking signal, so disallowing it does not touch regular search visibility. Because it piggybacks on Google's common crawlers, Google-Extended follows the published IP ranges for those crawlers rather than having a separate range of its own. MarketHQ tracks how brands appear in Gemini's answers as part of its wider AI visibility tracking across ChatGPT, Claude, Gemini, Perplexity, Grok, and DeepSeek.

Facts

Should you block it?

Disallowing Google-Extended keeps a site's content out of future Gemini training and out of the material Gemini uses to ground its answers, which appeals to a publisher that wants tighter control over how its work feeds AI models. The tradeoff is that Gemini is one of the AI assistants people increasingly ask for recommendations and comparisons, so opting out of this training and grounding data can make a brand less likely to be accurately represented when someone asks Gemini about its category. Google is explicit that none of this affects a site's regular Google Search ranking or inclusion, so a site does not have to weigh search visibility against this choice; it is purely about Gemini. A brand actively trying to show up well in AI answers, including through tools like MarketHQ that track AI visibility, generally benefits from leaving Google-Extended allowed so Gemini has current information to draw from.

How to block it

Add this to robots.txt to opt out of Google-Extended: user-agent: Google-Extended disallow: / This only affects training and grounding data for future Gemini models; it has no effect on Google Search inclusion or ranking.

Related

• AI crawler directory — every AI crawler's robots.txt token, purpose and facts in one place.
• Free AI crawler checker — check which AI crawlers a domain's robots.txt actually allows or blocks.
• Glossary — definitions of the AI-visibility terms that come up alongside crawler behavior.