Gemma 3 and o3-mini don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o3-mini shipped 40 days before Gemma 3, so benchmark comparisons should account for the intervening progress.

Gemma 3 is open weight, while o3-mini is proprietary.

Direct benchmark comparisons are unavailable — Gemma 3 and o3-mini don't publish scores on any of the same benchmarks.