Gemini 4 Carbon in GitHub Copilot vs Argon: Test by Dec 1

On December 1, 2026, GitHub will double the pricing for Gemini 4 Carbon in GitHub Copilot. The new rates will be double the existing per token costs for both input and output tokens. Before this price increase, Carbon was billed at $2.00 per million input tokens and $10.00 per million output tokens. After December 1, the input rate will increase to $4.00 per million and the output rate to $20.00 per million.

The decision to use Carbon in Copilot is recommended for short trials on difficult agentic tasks during the introductory rate period until November 30, 2026. For everyday work, it is suggested to use a faster model like Gemini 4 Argon. The billing for Carbon is per token at provider list pricing, meaning you pay for the actual tokens consumed during each task, rather than a premium-request multiplier.

Gemini 4 Carbon is currently available in GitHub Copilot Pro+, Max, Business and Enterprise plans, but not in the free or pro versions. Access is managed through the model policy on Business and Enterprise plans, allowing admins to enable or disable the model as needed.

When selecting Carbon in Copilot and testing it, update your editor or CLI to the latest release. Then, look for Gemini 4 Carbon in the model picker within Copilot Chat or the agent view on supported surfaces. To get accurate results, run three or four representative tasks with both Carbon and your usual model. Record the credits spent, correction rounds, and whether the changes merged without edits. Compare the cost per accepted change to determine the most cost-effective option.