Gemini
Gemini grounds answers with Google Search: the model decides whether a search would help, generates one or more queries, synthesizes the results and returns inline citations that link parts of the answer to source URLs. Google-Extended lets you opt out of Gemini training and of grounding in the Gemini app and Vertex AI, without affecting Google Search.
How grounding works
The Gemini API documentation lays out the flow:[1]
- The app sends the prompt with the Google Search tool enabled.
- The model “analyzes the prompt and determines if a Google Search can improve the answer.”
- If needed, it “automatically generates one or multiple search queries and executes them.”
- It processes the results and writes a response.
- The response includes “inline annotations containing the citations” that link spans of text to source URLs, plus the search queries used and search suggestions.
Because the searches run against Google Search, pages that do well in Google are the candidates for Gemini citations. Vendor-documented
Google-Extended
Google-Extended is a robots.txt product token with no separate HTTP user agent; crawling uses existing Google user agents. It controls whether content Google crawls may be used “for training future generations of Gemini models” and “for grounding” in Gemini Apps and Grounding with Google Search on Vertex AI. It “does not impact a site’s inclusion in Google Search nor is it used as a ranking signal.”[2] Vendor-documented
User-agent: Google-Extended Disallow: /
The trade-off: disallowing Google-Extended also removes your content from grounding in the Gemini app, so Gemini cannot cite you there. AI Overviews and AI Mode in Search are controlled separately (see Google AI features).
Gemini as a voice assistant
Gemini is replacing Google Assistant. Google offers Gemini for Home on speakers and displays,[3] and 9to5Google reported that Google would begin removing Assistant from Android phones on September 4, 2026.[4] See voice assistants.
How to be cited by Gemini
- Win the Google fundamentals: indexed, relevant, helpful pages (see Google AI features). Vendor-documented
- Do not disallow Google-Extended if you want Gemini app grounding. Vendor-documented
- Keep entity facts consistent, because Gemini answers about brands often mix Knowledge Graph facts with web sources (see entities). Practitioner practice
Frequently asked questions
Does blocking Google-Extended hurt my Google rankings?
No. Google says Google-Extended does not affect inclusion in Google Search and is not a ranking signal.
Does Gemini show citations?
Yes. Grounded responses include citations; the API returns inline annotations mapping text to source URLs.
Is Gemini the same as AI Mode?
No. Both use Google Search, but AI Mode is a Search feature governed by Search controls, while the Gemini app's grounding is governed by Google-Extended.
See also
References
Pages accessed September 28, 2026 unless a date is given. See all sources and our editorial policy.
- ^ "Grounding with Google Search (Gemini API)". Google AI for Developers.
- ^ "Google’s common crawlers (including Google-Extended)". Google Search Central. Last updated July 14, 2026.
- ^ "Learn about Gemini for Home voice assistant". Google Home and Nest Help.
- ^ "Google Assistant shutting down on Android, Wear OS in September". 9to5Google. Published August 4, 2026.