DeepSeek V2.5 and Gemini 3.1 Flash don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. DeepSeek V2.5 shipped 543 days before Gemini 3.1 Flash, so benchmark comparisons should account for the intervening progress.

DeepSeek V2.5 is open weight, while Gemini 3.1 Flash is proprietary.

Direct benchmark comparisons are unavailable — DeepSeek V2.5 and Gemini 3.1 Flash don't publish scores on any of the same benchmarks.