Devstral 2 2512 vs Mistral Small 4

Across our 12-test suite, Devstral 2 2512 wins 3 benchmarks, Mistral Small 4 wins 2, and 7 are tied.

Devstral 2 2512's wins:

• Constrained rewriting (5 vs 3): Devstral 2 2512 ties for 1st of 53 models on our compression-within-character-limits test; Mistral Small 4 ranks 31st. This is a meaningful gap for summarization, copy editing, and prompt compression tasks.
• Classification (3 vs 2): Devstral 2 2512 ranks 31st of 53; Mistral Small 4 ranks 51st — near the bottom of our tested field. If accurate categorization or routing is central to your pipeline, Mistral Small 4 is a notable weak point.
• Long context (5 vs 4): Devstral 2 2512 ties for 1st of 55 models on retrieval accuracy at 30K+ tokens; Mistral Small 4 ranks 38th. Both share a 262,144-token context window, but Devstral 2 2512 makes better use of it in our testing.

Mistral Small 4's wins:

• Safety calibration (2 vs 1): Mistral Small 4 ranks 12th of 55 on refusing harmful requests while permitting legitimate ones; Devstral 2 2512 ranks 32nd with a score of 1 — the bottom quartile across our tested models. This matters for consumer-facing deployments.
• Persona consistency (5 vs 4): Mistral Small 4 ties for 1st of 53; Devstral 2 2512 ranks 38th. For chatbots or role-defined agents that must maintain character, Small 4 has a clear edge.

Ties (7 benchmarks): Both models score identically on structured output (5/5, tied for 1st of 54), strategic analysis (4/5, rank 27 of 54), creative problem solving (4/5, rank 9 of 54), tool calling (4/5, rank 18 of 54), faithfulness (4/5, rank 34 of 55), agentic planning (4/5, rank 16 of 54), and multilingual (5/5, tied for 1st of 55). On these shared scores, there is no performance reason to pay Devstral 2 2512's premium.

Devstral 2 2512 costs $0.40/M input tokens and $2.00/M output tokens. Mistral Small 4 costs $0.15/M input and $0.60/M output — roughly 2.7× cheaper on input and 3.3× cheaper on output. At 1M output tokens/month, that gap is $1,400 vs $600. At 10M tokens, it's $14,000 vs $6,000. At 100M tokens, you're looking at $140,000 vs $60,000 — an $80,000 annual difference. Developers running high-volume inference pipelines, chatbots, or classification services should weight this heavily. The cost premium for Devstral 2 2512 is only justified if your workload specifically benefits from its wins: constrained rewriting, long-context retrieval, or agentic coding scenarios where its 123B-parameter architecture pays off.

Choose Devstral 2 2512 if: Your workload centers on agentic coding, long-document retrieval (30K+ tokens), constrained text compression, or classification routing — and you can absorb $2.00/M output tokens. Its description explicitly targets agentic coding, and our long-context and constrained-rewriting scores back that positioning.

Choose Mistral Small 4 if: You need multimodal inputs (it accepts images; Devstral 2 2512 does not per the payload), a safer response profile for consumer-facing products (ranks 12th vs 32nd on safety calibration in our tests), strong persona consistency for character-driven agents (scores 5 vs 4), or you're running at volume where the $0.60/M vs $2.00/M output cost difference compounds significantly. At 10M+ output tokens/month, the cost savings alone likely outweigh any performance difference on the 7 tied benchmarks.