Gemini 4 Carbon: Google's new cyber-focused frontier model

What happened

Google DeepMind announced Gemini 4 Carbon on October 28. Google calls it its strongest model, with state-of-the-art cybersecurity and long-horizon capabilities (Google DeepMind).

Carbon builds on Gemini 4 Argon, which launched two weeks ago. According to Google, it ranks first on the recently updated v5.0 of the Artificial Analysis Intelligence Index with a score of 59. Google reports significant gains in coding, agentic tasks and capabilities critical for cyber defense.

Cybersecurity is the big jump

Google highlights three external benchmarks, all evaluated without guardrails:

• SEC-bench Pro, finding real vulnerabilities: 88.2%.
• ExploitGym, checking which vulnerabilities are exploitable: 54.8%.
• Collinear's CWE-bench, patching at the root cause: 71.0%.

On internal benchmarks, Carbon has more than a 2x higher success rate than Argon at generating secure code. The Chrome team reported that it performed more than 10x better than another lab's large frontier model at generating high-quality patches. Wiz also sees Carbon leading on web penetration testing benchmarks.

Source: Google DeepMind. Gemini 4 Carbon benchmark results alongside Gemini 4 Argon, GPT-6 Astra, Claude Opus 5.5 and Claude Fable 5.1.

Even Google's own table is not all first places. GPT-6 Astra leads on FrontierSWE 2 (65.5% versus Carbon's 61.2%), and Claude Opus 5.5 leads on the OSWorld-2.1 offline subset (87.2% versus 81.5%).

Agent runs that last for days

Carbon is built for sustained agentic workflows. Google says that internally it ran for days, persisting through dead ends to root-cause and patch subtle bugs across large codebases and low-level systems.

Web development improved as well: Carbon gained 89 Elo points on WebDev Arena and sits in fourth place with 1769.

Safety and alignment

Carbon builds on Argon's multi-layered safety and security stack. Google reports these results:

• Terminal-Bench 4.0: successful cheating at 0.0% and cheating attempts at 0.4%, while overall accuracy improved.
• In live coding environments with internal teams, high-severity misalignment alerts dropped by almost 80%.
• In internal testing, it makes roughly half as many unsupported claims as Argon.
• Overreach fell by 26% and under-service by 29% on multi-step plans.
• Gray Swan IPI benchmark: 0.0% prompt injection attack success, down from Argon's 0.7%.

Who gets access, and at what price

Google is taking a deliberate rollout and is part of the US government's voluntary pre-release model testing process. Starting this week, a subset of cyber defenders gets access, followed by more trusted partners through the Fairwind Program. Developers, businesses and consumers will get it as soon as possible, according to Google, with no date given.

The introductory price matches Argon: $2 per million input tokens and $10 per million output tokens, with cached input tokens 95% cheaper. After the introductory period, the price rises to $4 and $20. Google did not say how long the introductory period lasts.

What it means for you

There is nothing to try yet: no API access, only cyber defense partners. If you build on Argon, the good news is that the introductory price is the same, so switching will be cost-neutral. Most of the numbers are Google's own measurements, though, so wait for independent tests before moving a pipeline over.