Devstral Small and o3-mini don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o3-mini shipped 110 days before Devstral Small, so benchmark comparisons should account for the intervening progress.

Devstral Small is open weight, while o3-mini is proprietary.

Direct benchmark comparisons are unavailable — Devstral Small and o3-mini don't publish scores on any of the same benchmarks.