Google releases Gemini 4 Hydrogen, the lowest-cost model in the Gemini 4 family

Google released Gemini 4 Hydrogen, the lowest-cost model in the Gemini 4 family, priced at $1.50 per million input tokens, $0.075 for cached input and $7.50 per million output tokens. Simon Willison notes that Carbon and Argon both cost $2.00/$0.10/$10.00 until Nov 30, 2026 and double from Dec 1, 2026, so Hydrogen is currently only about 25% cheaper than its larger siblings, a gap that widens to roughly 75% after the increase. Hydrogen is also the new free tier model and will power AI features in Google Search.