Gemini 4 Carbon arrives in Google Search AI Mode for Ultra subscribers
Google has made Gemini 4 Carbon available in AI Mode within Google Search, but only for Google AI Ultra subscribers. The model is described as Google's strongest yet, with frontier performance in cybersecurity and long-horizon agentic workflows spanning software engineering, scientific reasoning and complex knowledge work.
The rollout covers Antigravity, the Gemini app and AI Mode in Search. Subscribers will see the option in the AI Mode model selector. Robby Stein of Google said the model brings deeper reasoning and better instruction following, aimed at tougher questions in AI Mode, while Rajan Patel said it reads user intent more accurately to support longer back-and-forth conversations.
For brands chasing citations in AI answers, the change means a more capable model is now handling some of the hardest queries in Search. Better intent reading and multi-turn dialogue give assistants more room to weigh and revisit sources mid-conversation, so the answers Ultra users see may draw on a different mix of pages than the standard AI Mode responses.
Reported by Search Engine Roundtable ↗
Topics: AI Mode, Google Search, Gemini