● Price: $1.50 in / $7.50 out per million tokens, flat across the whole 1M context. Cache hits $0.075.
● The headline: it scores 51 on the Artificial Analysis Intelligence Index against Argon’s 50 — the smaller model beating the flagship four weeks after Argon launched.
● Speed: 2.5x faster than 3.8 Flash at default. Partners report 2x to 2.8x faster runs and 12–23% fewer tokens.
● Where: Gemini API and AI Studio on all tiers, Android Studio, the Gemini app, and Google Search globally — free users included.
Google announced Gemini 4 Hydrogen on 12 November, positioning it as the “daily driver for agentic workflows” rather than a deep reasoning model. It replaces 3.8 Flash and adds a fourth thinking level, xhigh, on top of low, medium and high.
The benchmark that matters most is Terminal-Bench 4.1, where Hydrogen scores 57% against 18.2% for 3.8 Flash — more than triple. Google also reports fabricated claims cut by more than five times against its predecessor. On agentic coding, SWE-sweep puts Hydrogen at 13.5% against Argon’s 4.3%.
| Benchmark |
Hydrogen |
Gemini 4 Argon |
| AA Intelligence Index |
51 (54 at xhigh) |
50 |
| SWE-sweep, agentic coding |
13.5% |
4.3% |
| Agents’ Last Exam v1.1 |
71.6% |
69.0% |
| OSWorld-2.1, offline subset |
77.6% |
74.7% |
| Vending-Bench 2, balance |
$14,549 |
$13,718 |
| Chartography |
66.6% |
71.6% |
Argon still wins where you would expect a bigger model to: Chartography, GraphWalks at 84.2%, SEC-bench Pro at 83.4% and Terminal-Bench 4.0 at 57.1%, none of which Google published a Hydrogen figure for. The honest read is that Hydrogen wins the agentic and tool-use benchmarks and Argon keeps the heavier reasoning ones.
Elsewhere Hydrogen takes 58.8% on HLE-Diamond, 52.3% on the Vals Tax Agent Bench for first place overall, 55.8% on Vals Legal Research for a tie at the top, 53.4% on the Multimodal Knowledge Agent set, and fifth on Agent Arena. Artificial Analysis puts cost per task at $0.29 at low effort rising to $3.16 at xhigh.
Full comparison: Hydrogen vs Argon, benchmark by benchmark · Hydrogen vs Claude Fable 5.2 on price. Listing: Gemini 4 Hydrogen.
Sources