Google released Gemini 4 Carbon, its "strongest model with frontier performance in cybersecurity capabilities and long-horizon agentic workflows across complex knowledge work, software engineering, and scientific reasoning," and it is now available in Google Search via AI Mode for subscribers.
Google wrote that Gemini 4 Carbon is "rolling out to all Google AI Ultra subscribers in Google Antigravity, the Gemini app, and AI Mode in Search."
You can see the option if you are a paid subscriber in the Google Search AI Mode selector:
Robby Stein from Google posted on X, "Shipping Gemini 4 Carbon in Search today for Google AI Ultra subs! With deeper reasoning & better instruction following, you’ll get more helpful responses for your toughest questions in AI Mode. I’ve loved using this internally – excited for more people to try it out."
Rajan Patel from Google also posted on X amd wrote, "We're bringing our latest frontier model to Search! One thing I really love: Gemini 4 Carbon better understands your intent so you can have deeper back and forth convos in Al Mode. Rolling out now to Google Al Ultra subscribers."
Glenn Gabe has been testing it and wrote on X, "I've been testing Carbon as part of the @GeminiApp early access program. It's insanely powerful. E.g. I used it to build a new version of one of my favorite Atari 2600 games, Pitfall. I did that via one prompt. It took a few minutes and it worked perfectly. :) -> Google rolls out Gemini 4 Carbon to paid API and AI Ultra users two weeks after releasing it to cyber defenders, and previews a swarm feature in Antigravity."
Forum discussion at X.