DeepSeek V3.1 Terminus and GPT-5 nano don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5 nano shipped 46 days before DeepSeek V3.1 Terminus, so benchmark comparisons should account for the intervening progress.

DeepSeek V3.1 Terminus is open weight, while GPT-5 nano is proprietary.

Direct benchmark comparisons are unavailable — DeepSeek V3.1 Terminus and GPT-5 nano don't publish scores on any of the same benchmarks.