gpt-oss-20b and Grok 2.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. gpt-oss-20b shipped 18 days before Grok 2.5, so benchmark comparisons should account for the intervening progress.

gpt-oss-20b is open weight, while Grok 2.5 is proprietary.

Direct benchmark comparisons are unavailable — gpt-oss-20b and Grok 2.5 don't publish scores on any of the same benchmarks.