Google has released Gemini 4 Hydrogen, a model for everyday coding and agentic workflows that is meant to replace Gemini 3.8 Flash. It offers four thinking levels, low, medium, high as the default, and a new xhigh tier, along with a one-million-token context window for both input and output. Pricing is $1.50 per million input tokens and $7.50 per million output tokens, and cache hits cost $0.075.
Google says Hydrogen scores 51 on the Artificial Analysis Intelligence Index at the default high level, ahead of Gemini 4 Argon at 50, and reaches 54 at xhigh. Google also says the model finishes tasks 2.5 times faster than Flash at the default level and cuts hallucinations by a factor of five. It is available in the Gemini API in AI Studio and Android Studio, in Google Antigravity for paying Pro and Ultra subscribers, in Gemini for Business, and in the Gemini app and Google Search.
Artificial Analysis puts the average cost per task at $1.87 at high and $3.16 at xhigh, because xhigh uses nearly twice as many output tokens. The independent evaluation gives Hydrogen 54 percent on Terminal-Bench 4.0 and 8 percent hallucinations on AA-Omniscience, and it finds the model weaker than Claude Sonnet 5.5 and GPT-6.1 Sol on agentic terminal work.
Why it matters if you build agents
Developers building agents can evaluate Hydrogen as a lower-cost option for routine coding and knowledge work that needs a large context window. The independent terminal scores suggest testing it before sending shell-heavy agent tasks to it. Token budgets should be checked closely at xhigh, where costs rise sharply.
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