Google released Gemini 4 Hydrogen on November 12. Developers can use it on the Gemini API’s free tier or pay for metered usage. Google positions it for everyday coding and tasks that require several steps, and positions Carbon and Argon for longer reasoning work.
What users can access
Google says Hydrogen is rolling out globally in Search and the Gemini app. Free Gemini app users get Hydrogen through automatic model selection when the app chooses it for a prompt. In Google Antigravity, access is available to paid Google AI Pro and Ultra subscribers. Antigravity’s new Orchestrator can switch between models such as Carbon and Hydrogen during a session. Google also lists access in AI Studio, Gemini for business and Google Sheets, with eligibility in Sheets depending on the subscription.
Developer pricing and limits
The stable Gemini API model ID is gemini-4-hydrogen. Standard paid rates are $1.50 per million input tokens and $7.50 per million output tokens. These rates apply across the full context window. Google charges $0.075 per million implicitly cached tokens and counts thinking tokens as output.
Input and output share a 1,048,576-token budget. A standard synchronous request can return up to 65,536 tokens. The long-decode option can use more of the shared budget for output. Free API requests cannot use Google Search grounding, which lets an API response draw on web results. That limit applies to the developer API.