Google rolls out Gemini 4 Hydrogen for complex Search questions

Google Search product vice president Robby Stein said Gemini 4 Hydrogen is now the default model in AI Mode and is being used for the hardest questions in AI Overviews. The company says the model can run simultaneous queries across relevant subtopics, giving users a wider range of links in responses.

Answers can also include more visual material, such as images, comparison tables, graphs and maps. In an example shared by Stein, the model generated an interactive animated driving simulation to explain how phones determine which highway lane a car is in when there is no cell service. Google also says the model has improved language understanding across all supported AI Mode languages.

Users can choose among four thinking levels: low, medium, high and the new “xhigh” option. Google says Gemini 4 Hydrogen makes “significant leaps in both speed and intelligence” over Gemini Flash 3.8 and “matches or outperforms some of the competing models in its class,” including Claude Sonnet 5.5 and GPT-6.1 Terra.

The model is available in Search, the Gemini app, all tiers of Google AI Studio, the Gemini API and Gemini for business. It is also available in Google Antigravity for Google AI Pro and Ultra subscribers.