Model comparison
Devstral Small 2505 vs o4-mini
o4-mini is the stronger model overall, scoring 41.6 to 33.9 on the Noometry Index. Devstral Small 2505 costs 13× less per token, which makes it the better buy when o4-mini's lead doesn't matter for your workload.
Last verified . 3 shared benchmarks.
Mistral AISummary
- They share 3 benchmarks with published results for both. Devstral Small 2505 scores higher in 0 categories and o4-mini in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where o4-mini leads 24.6 to 19.1.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 37.7% for Devstral Small 2505 and 67.6% for o4-mini.
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.10 / $4.40 for o4-mini.
- o4-mini accepts more context: 200K tokens versus 128K.
- Devstral Small 2505 has downloadable open weights; the other is API-only.
Side by side
| Devstral Small 2505 | o4-mini | |
|---|---|---|
| Provider | Mistral AI | OpenAI |
| Noometry Index | 33.9 | 41.6 |
| Released | 2025-05-07 | 2025-04-16 |
| Weights | Open | Proprietary |
| Context window | 128K | 200K |
| Max output | 128K | 100K |
| Input $ / M tokens | $0.10 | $1.10 |
| Output $ / M tokens | $0.30 | $4.40 |
| Results tracked | 4 | 60 |
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Category by category
Coding o4-mini leads
Devstral Small 2505: 38.6 (#160), o4-mini: 41.6 (#110)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | 45% |
| Aider Polyglot | — | 72% |
| SciCode | 28.8% | — |
| GSO | — | 3.6% |
| WeirdML | — | 52.6% |
| LMArena Coding | — | 1369 |
| CadEval | — | 62% |
| ALE-Bench | — | 826.17 |
| AlgoTune | — | 1.72 |
Agentic & Tool Use Not comparable
Devstral Small 2505: —, o4-mini: 32.3 (#57)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 53.2% |
| GDPval | — | 25.3% |
| METR Time Horizons | — | 63.9% |
Reasoning o4-mini leads
Devstral Small 2505: 19.1 (#243), o4-mini: 24.6 (#143)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | 67.6% |
| CritPt | 0% | 0.6% |
| ARC-AGI-2 | — | 6.1% |
| SimpleBench | — | 38.7% |
| ARC-AGI-1 | — | 58.7% |
| Chess Puzzles | — | 26% |
| EnigmaEval | — | 9.2% |
| LMArena Hard Prompts | — | 1351 |
| Mystery Game Puzzles | — | 5% |
| DTBench | — | 77.6% |
| LMCA | — | 26.5% |
| Epoch Capabilities Index | — | 145.63 |
| ForecastBench | — | 61.8 |
Math Not comparable
Devstral Small 2505: —, o4-mini: 40.2 (#79)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 36.1% |
| FrontierMath Tier 4 | — | 4.9% |
| OTIS Mock AIME 2024-2025 | — | 81.7% |
| Omni-MATH | — | 72% |
| LMArena Math | — | 1390 |
| MATH Level 5 | — | 97.8% |
| FrontierMath (Feb 2025 set) | — | 24.8% |
| FrontierMath Tier 4 (v1) | — | 6.3% |
Knowledge Not comparable
Devstral Small 2505: —, o4-mini: 43.5 (#83)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| GPQA Diamond | — | 79.6% |
| Humanity's Last Exam | — | 18.1% |
| SimpleQA Verified | — | 19.6% |
| MMLU-Pro | — | 82% |
| Confabulations | — | 15.8% |
| Vectara Hallucination Rate | — | 18.6% |
| GPQA (HELM) | — | 73.5% |
| LMArena Expert | — | 1344 |
Multimodal Not comparable
Devstral Small 2505: —, o4-mini: 39.5 (#46)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| LMArena Vision | — | 1194 |
| GeoBench | — | 64% |
| VPCT | — | 57.5% |
Multilingual Not comparable
Devstral Small 2505: —, o4-mini: 47.2 (#149)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| LMArena Non-English | — | 1336 |
| LMArena Chinese | — | 1355 |
| LMArena French | — | 1362 |
| LMArena German | — | 1336 |
| LMArena Japanese | — | 1308 |
| LMArena Korean | — | 1313 |
| LMArena Russian | — | 1334 |
| LMArena Spanish | — | 1346 |
Instruction Following Not comparable
Devstral Small 2505: —, o4-mini: 75.4 (#63)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| IFEval | — | 92.8% |
| LMArena Instruction Following | — | 1321 |
Long Context Not comparable
Devstral Small 2505: —, o4-mini: 45.5 (#31)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| Fiction.LiveBench | — | 77.8% |
| LMArena Longer Query | — | 1315 |
Writing & Preference Not comparable
Devstral Small 2505: —, o4-mini: 54.2 (#148)
| Benchmark | Devstral Small 2505 | o4-mini |
|---|---|---|
| LMArena Text | — | 1353 |
| LMArena Creative Writing | — | 1294 |
| Short-Story Creative Writing | — | 75% |
| WildBench | — | 85.4% |
| LMArena Multi-Turn | — | 1350 |
Frequently asked questions
Is Devstral Small 2505 better than o4-mini?
o4-mini is the stronger model overall, scoring 41.6 to 33.9 on the Noometry Index. Devstral Small 2505 costs 13× less per token, which makes it the better buy when o4-mini's lead doesn't matter for your workload.
Which is cheaper, Devstral Small 2505 or o4-mini?
Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; o4-mini lists at $1.10 and $4.40.
Is Devstral Small 2505 or o4-mini better for coding?
o4-mini scores higher on coding benchmarks: 41.6 versus 38.6 in the Noometry coding category.
Which has the bigger context window?
o4-mini does, with 200K tokens against 128K.
How many benchmarks do Devstral Small 2505 and o4-mini share?
3 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and o4-mini has 60.