Devstral Small 2 (24B) and GPT-5.6 Luna don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Devstral Small 2 (24B) shipped 199 days before GPT-5.6 Luna, so benchmark comparisons should account for the intervening progress.

Devstral Small 2 (24B) is open weight, while GPT-5.6 Luna is proprietary.

Direct benchmark comparisons are unavailable — Devstral Small 2 (24B) and GPT-5.6 Luna don't publish scores on any of the same benchmarks.