Model comparison
Mercury 2.5 vs Mistral Small 3.1
Mistral Small 3.1 has enough public results to be ranked (#263); Mercury 2.5 does not yet, so treat this comparison as directional.
Last verified . 0 shared benchmarks.
Mistral AISummary
- The widest gap is in math, where Mercury 2.5 leads 22.4 to 13.7.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $0.35 / $0.56 for Mistral Small 3.1.
- Mercury 2.5 accepts more context: 260K tokens versus 128K.
- Mistral Small 3.1 has downloadable open weights; the other is API-only.
Side by side
| Mercury 2.5 | Mistral Small 3.1 | |
|---|---|---|
| Provider | Inception | Mistral AI |
| Noometry Index | 30.2 | 31.4 |
| Released | 2026-09-08 | 2025-03-17 |
| Weights | Proprietary | Open |
| Context window | 260K | 128K |
| Max output | 66K | 102K |
| Input $ / M tokens | $0.04 | $0.35 |
| Output $ / M tokens | $0.15 | $0.56 |
| Results tracked | 2 | 28 |
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Category by category
Coding Not comparable
Mercury 2.5: —, Mistral Small 3.1: 37.7 (#175)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | — | 1309 |
| ALE-Bench | 301.65 | — |
Reasoning Not comparable
Mercury 2.5: —, Mistral Small 3.1: 18.9 (#249)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| Chess Puzzles | — | 1% |
| LMArena Hard Prompts | — | 1278 |
| Epoch Capabilities Index | — | 127.48 |
Math Mercury 2.5 leads
Mercury 2.5: 22.4, Mistral Small 3.1: 13.7 (#295)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 3.9% |
| ProofBench | 3% | — |
| Omni-MATH | — | 24.8% |
| LMArena Math | — | 1261 |
Knowledge Not comparable
Mercury 2.5: —, Mistral Small 3.1: 22.6 (#266)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| GPQA Diamond | — | 41.9% |
| MMLU-Pro | — | 61% |
| GPQA (HELM) | — | 39.2% |
| LMArena Expert | — | 1258 |
Multimodal Not comparable
Mercury 2.5: —, Mistral Small 3.1: 32.6 (#93)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | — | 1136 |
Multilingual Not comparable
Mercury 2.5: —, Mistral Small 3.1: 41.4 (#204)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | — | 1255 |
| LMArena Chinese | — | 1254 |
| LMArena French | — | 1270 |
| LMArena German | — | 1266 |
| LMArena Japanese | — | 1210 |
| LMArena Korean | — | 1206 |
| LMArena Russian | — | 1263 |
| LMArena Spanish | — | 1283 |
Instruction Following Not comparable
Mercury 2.5: —, Mistral Small 3.1: 63.8 (#225)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| IFEval | — | 75% |
| LMArena Instruction Following | — | 1264 |
Long Context Not comparable
Mercury 2.5: —, Mistral Small 3.1: 39.5 (#172)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | — | 1300 |
Writing & Preference Not comparable
Mercury 2.5: —, Mistral Small 3.1: 37.2 (#254)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | — | 1278 |
| LMArena Creative Writing | — | 1253 |
| EQ-Bench Creative Writing | — | 761 |
| WildBench | — | 78.8% |
| LMArena Multi-Turn | — | 1270 |
Frequently asked questions
Is Mercury 2.5 better than Mistral Small 3.1?
Mistral Small 3.1 has enough public results to be ranked (#263); Mercury 2.5 does not yet, so treat this comparison as directional.
Which is cheaper, Mercury 2.5 or Mistral Small 3.1?
Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; Mistral Small 3.1 lists at $0.35 and $0.56.
Which has the bigger context window?
Mercury 2.5 does, with 260K tokens against 128K.
How many benchmarks do Mercury 2.5 and Mistral Small 3.1 share?
0 benchmarks have published results for both models. Mercury 2.5 has 2 scored results on Noometry and Mistral Small 3.1 has 28.