Mistral Small 3.1 and o1-preview don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o1-preview shipped 186 days before Mistral Small 3.1, so benchmark comparisons should account for the intervening progress.

Mistral Small 3.1 is open weight, while o1-preview is proprietary.

Direct benchmark comparisons are unavailable — Mistral Small 3.1 and o1-preview don't publish scores on any of the same benchmarks.