Gemini 4 Carbon arrives in the Gemini app for AI Ultra subscribers

What changed

Google has started rolling out Gemini 4 Carbon in the Gemini app, according to 9to5Google. The model was previewed at the end of October and is now available through the app's model picker.

The picker labels 4 Argon as the option for code and analysis, while 4 Carbon is marked for the most complex work. Google says Argon still suits most everyday software and knowledge tasks, and describes Carbon as the model for jobs that push a model's intelligence to its limits.

Where Carbon is meant to shine

Google points to demanding examples such as multi-step coding and debugging, plus open-ended scientific research. The company also says Carbon can follow strict schemas and formatting to produce precise spreadsheets, presentations and reports for legal, finance and enterprise work.

The model is also positioned for engineering work that needs several agents to cooperate, such as large code migrations, investigations that span subsystems, and architectural redesigns. Google adds that stronger visual design and spatial reasoning carry over to 3D game development and creative coding.

Benchmark claims

Google argues that existing benchmarks fail to capture how agents read dense files containing charts, images, blueprints and tables. It therefore worked with Artificial Analysis on a new benchmark called Multimodal Knowledge Agents, which covers 200 tasks in agentic workflows.

According to Google, Carbon ranks first on that benchmark while using three times fewer tokens than the next best model. These are Google's own figures and have not been independently verified.

Antigravity and the swarm preview

To demonstrate Carbon on larger projects, Google Antigravity is previewing a feature called /swarm. It turns a single prompt into a coordinated team of agents that can be tracked in real time.

Developers can give Carbon the roles that need the deepest reasoning, such as architectural design, coordination and auditing. These run alongside faster, lighter models in parallel isolated workspaces, with adversarial verifiers checking every change.

Pricing and availability

Carbon costs $2 per million input tokens and $10 per million output tokens as an introductory rate until 30 November 2026. After that, the price rises to $4 per million input tokens and $20 per million output tokens.

Enterprises can try Carbon through the API, Gemini for business, Google Antigravity, or agents such as CodeMender and AlphaEvolve. Google is also offering researchers a chance to apply for six months of free access to both models at Antigravity's highest usage tier, subject to eligibility, and cyber defenders can apply to join the Fairwind Program.

Who is affected

The launch removes Gemini 3.1 Pro from the Gemini app's model picker, so users of that version will need to switch to Argon or Carbon. Argon remains available and Google positions it as the default choice for most work.