Google puts Gemini 4 Hydrogen in Search for everyone, and says it edges past Argon

It's how Gemini 4 reaches everyone, and Google built a tool that hands work between it and Carbon mid-session.

By Think Facility · November 12, 2026 · Google AI models

On November 12, 2026, Google released Gemini 4 Hydrogen, the newest model in its Gemini 4 line. Koray Kavukcuoglu, Google's Chief AI Architect, introduced it as the quick, everyday member of the family, built for agents that write code, run tests and check their own changes.

It also reaches far more people than Gemini 4 has so far. Hydrogen went live the same day in Google Search for all users, in the Gemini app, and in the Gemini API at $1.50 per million input tokens and $7.50 per million output.

Model: Gemini 4 Hydrogen
Released: Nov 12, 2026
API price: $1.50 per million input tokens, $7.50 per million output tokens
Context window: 1 million tokens
Artificial Analysis Intelligence Index: 51 at high, 54 at xhigh

Where it sits next to Carbon and Argon

Google calls Carbon and Argon its frontier models, the ones for long, hard reasoning. Carbon opened to paying developers the day before, as we reported. Hydrogen is meant to be the fast one.

A curved glass and silver office building with a glass tower at one end, and a round flower bed with a small Google sign in front — An office building at the Googleplex, Google's headquarters in Mountain View, California. Photo: Håkan Dahlström from Malmö, Sweden, CC BY 2.0, via Wikimedia Commons

Even so, Google says it scores 51 on the Artificial Analysis Intelligence Index at its default setting. That's a point above Argon's 50, and it reaches 54 at a new xhigh thinking level.

The bigger jump is over the model it replaces. Against Gemini 3.8 Flash, Google says Hydrogen finishes tasks 2.5 times faster at its default setting and more than triples the Terminal-Bench 4.1 score, from 18.2% to 57%. Those are Google's own numbers, and we haven't seen an independent run yet.

The price is flat across the whole 1 million-token context window, so a long document costs the same per token as a short question.

One session, two models

Alongside Hydrogen, Google added a feature called Orchestrator to Google Antigravity. Instead of one model running a task start to finish, Orchestrator switches between models such as Carbon and Hydrogen inside the same session. Carbon can act as coordinator while Hydrogen runs the worker and verifier agents that build and test changes side by side.

Orchestrator reached near-Carbon task success rates while, on average, consuming 24% less quota and completing 19% faster

From Introducing Gemini 4 Hydrogen for Agentic Workflows

Quota is the number subscribers will feel. If that saving holds on real work, a paid plan gets through more tasks before it hits its cap, at close to Carbon's success rate.

What Google says about safety

Google says Hydrogen cuts misaligned actions and task shortcutting by 12x across its tool-use and coding evaluations, compared with 3.8 Flash. When a task is impossible or blocked, it's up to 2x less likely to bypass permission boundaries, and it scored a 96.7% honesty rate on Google's internal agent honesty evaluation.

Hydrogen also preserves 99.9% chain-of-thought legibility with zero deceptive reasoning edits across more than 200,000 audited turns

From Introducing Gemini 4 Hydrogen for Agentic Workflows

Most of those results come from Google's own tests. The one outside benchmark the post names is Gray Swan's test of indirect prompt injection, where Google says Hydrogen is more than 2.3x more resilient.

What changes in Search

For most people, Hydrogen arrives without them picking it. Robby Stein, Google's VP of Product for Search, writes that "This is the biggest model upgrade to Search yet." Google says Search will now handle multi-part questions and highly specific requests more precisely, with more images and comparison tables in its answers.

For anyone who runs a website, the claim to watch is about links. Hydrogen powers more of the parallel searches Google runs behind each answer (it calls this query fan-out), and Google says that connects people to a broader range of sites than before. Stein's post doesn't give a figure for how much broader, or say what it means for traffic.

In the Gemini app, a footnote says free users get Hydrogen through auto model selection when it suits the prompt. Paid Google AI Pro and Ultra subscribers can also use it in Google Antigravity.