Major · AI Search · AI
Google makes Gemini 4 Hydrogen the new default model across AI Search
Google says Gemini 4 Hydrogen is now available globally in Search, becoming the default model in AI Mode and powering the hardest questions in AI Overviews. The company describes improved intent handling, query fan-out, linking, visual responses and language understanding. The source notes that the change may affect AI features rather than core rankings, but Google has not confirmed that distinction here.
Why it matters: Marketers need to reassess how content is structured and discovered as Search expands query fan-out, visual answers, richer language understanding and AI-driven response formats. The likely effects are significant but mixed: better matching and new discovery opportunities for some sites, alongside greater competition for visibility within AI-generated results.

