Google Launches Gemini 4 Hydrogen, Replacing Gemini 3.8 Flash Across Search and Products

Google DeepMind has officially released Gemini 4 Hydrogen, the next-generation flagship model that replaces Gemini 3.8 Flash as the default model powering Google Search's AI Mode and other Google products. The model features significantly improved handling of complex, multi-step questions, with DeepMind citing advances in reasoning and instruction-following as core improvements over prior versions. Gemini 4 Hydrogen represents the first full generational step in the Gemini 4 family, moving beyond the incremental updates that characterized the 3.x line. For developers building on the Gemini API, this upgrade means access to a more capable base model for search-grounded agents and RAG pipelines. Teams evaluating frontier models for reasoning-heavy tasks should benchmark Hydrogen immediately, as it may shift the competitive landscape for complex query handling.