DeepSeek V2.5 and o1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. DeepSeek V2.5 shipped 91 days before o1, so benchmark comparisons should account for the intervening progress.

DeepSeek V2.5 is open weight, while o1 is proprietary.

Direct benchmark comparisons are unavailable — DeepSeek V2.5 and o1 don't publish scores on any of the same benchmarks.