The crawler question for Gemini is Google-Extended (controls Gemini training use; Googlebot still crawls for Search). Blocking is a real option with a real cost, and the two directions are not symmetric. Gemini is grounded in Google Search, so its source pool overlaps heavily with what already ranks. Of the six, it is the one where classic SEO work transfers most directly: a page that moves from position 30 to position 5 changes its odds here in a way it does not on ChatGPT.
How Gemini actually decides
Gemini is grounded in Google Search, so its source pool overlaps heavily with what already ranks. Of the six, it is the one where classic SEO work transfers most directly: a page that moves from position 30 to position 5 changes its odds here in a way it does not on ChatGPT.
Its citations skew toward pages that already rank in Google Search for the same query, plus Google’s own properties. In practice that means the surfaces worth auditing first are top-ranking organic results, YouTube, Google Business Profiles for local queries, structured data.
The method, in order
Know which agent does what: Google-Extended (controls Gemini training use; Googlebot still crawls for Search). Training access and answer-time retrieval are usually separate controls, and blocking the wrong one achieves the opposite of what was intended.
Decide what you are protecting. Blocking reduces the chance of being quoted without attribution; it also reduces the chance of being recommended at all.
Consider the asymmetry. Being absent from Gemini is easy to cause and slow to undo, even here, where retrieval is live, reputation lags access.
If you do block, block deliberately and document it, so a future traffic investigation does not spend a week rediscovering it.
Re-check after any robots.txt change that the agent you meant to allow is still allowed.
The honest caveat
Blocking Google-Extended stops your content training Gemini but does not remove you from grounded answers: the two are separate controls and are widely confused.
Cituna checks Gemini daily alongside the other five engines, ChatGPT, Perplexity, Gemini, Claude, Grok and Google AI Overviews, on the $39 Starter, and pairs the result with Google Search Console so a change here can be tied to real clicks. We do not track Microsoft Copilot.
Drafted with AI assistance from our own research and Search Console data, and reviewed by Rahul A before publishing. Rules and prices change; check the linked official source before you act.