Gemini 4 Hydrogen Reaches General Availability in GitHub Copilot

GitHub's changelog entry for Gemini 4 Hydrogen is about access, not performance. It says who can choose Google's new model inside Copilot, where, how it is billed, and who controls it (GitHub changelog). GitHub describes Hydrogen as Google's latest Flash model, designed for fast agentic coding, tool use and multistep workflows, with better instruction following than Gemini 3.8 Flash. Google's own positioning of Hydrogen as the faster, everyday counterpart to Gemini 4 Carbon is in its launch announcement. The changelog itself gives no benchmark numbers.

The model is generally available to Copilot Pro, Pro+, Max, Business and Enterprise users. It appears in the model picker across GitHub's surfaces, including VS Code, Visual Studio, JetBrains IDEs, Xcode, Eclipse, the Copilot CLI, the Copilot coding agent, the GitHub Copilot app, github.com, GitHub Mobile and the Copilot SDK. It is billed at Google's list price under Copilot's usage-based billing. The rollout is gradual, so some users may not see it yet.

The detail that matters for organizations is the admin default. On Business and Enterprise plans, new models are switched on automatically under default model enablement. Hydrogen will appear for developers unless an administrator has turned off that global default or disables this model specifically in Copilot's model policy. Teams that want to review each new model before developers can use it need to change that setting. Gemini 4 Carbon, which Google positions for the hardest problems, is also generally available in Copilot with the same usage-based billing at provider list price and the same default-enablement rule, though only from Copilot Pro+ upward.