Google said Thursday it is putting Gemini 4 Hydrogen into Google Search worldwide for all users, describing the change as its largest model upgrade to Search so far¹.

The Search post said Hydrogen is meant to handle more complicated questions, including multi-part queries and typos, and to follow instructions and tool calls more closely¹. Google also said the model would "supercharge" query fan-out so Search runs simultaneous subtopic queries and surfaces a broader set of links¹.

The company said answers would include more images, structured layouts, comparison tables and custom tools, and that language understanding would improve across supported AI Mode languages¹.

Techmeme, summarizing 9to5Google, said Hydrogen is also available in Google AI Studio, the Gemini API, Search, and paid Google AI Pro and Ultra tiers in Antigravity, after this week's Carbon launch².

Two days earlier, Engadget and The Verge reported Google widening Gemini 4 Carbon after an October preview for some cybersecurity users^3,4. Google said Carbon is aimed at multi-step coding and scientific research, while Argon remains the better fit for most software engineering^3,4.

The Verge said Carbon is rolling out to paying developers and enterprises and to AI Ultra subscribers in the Gemini app, Search AI Mode and Antigravity, and that availability for lower-tier or free users was unclear⁴. It reported introductory API pricing of $2 per million input tokens and $10 per million output tokens, with those rates set to rise at the end of November⁴.

Engadget said Google is giving 10,000 scientists six months of free Carbon access and that AI Ultra costs $100 a month³. The Verge also described an Antigravity swarm preview that would turn one prompt into a coordinated set of agents⁴.

Independent tests of Hydrogen in Search were not in the assigned coverage. Product claims about intent, visuals and linking come from Google¹.