Model comparison
Mercury 2.5 vs Mistral Small 3.1
Mercury 2.5 is the stronger model overall, scoring 33.5 to 31.7 on the Noometry Index.
Last verified . 0 shared benchmarks.
Mistral AISummary
- The widest gap is in math, where Mercury 2.5 leads 23.3 to 14.7.
- 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 | 33.5 | 31.7 |
| 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 | 4 | 28 |
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Category by category
Coding Mercury 2.5 leads
Mercury 2.5: 39.5 (#156), Mistral Small 3.1: 38.3 (#179)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| SciCode | 38.5% | — |
| LMArena Coding | — | 1309 |
| ALE-Bench | 301.65 | — |
Reasoning Mercury 2.5 leads
Mercury 2.5: 22.4 (#193), Mistral Small 3.1: 19.7 (#254)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| CritPt | 0% | — |
| Chess Puzzles | — | 1% |
| LMArena Hard Prompts | — | 1278 |
| Epoch Capabilities Index | — | 127.48 |
Math Mercury 2.5 leads
Mercury 2.5: 23.3 (#272), Mistral Small 3.1: 14.7 (#301)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 3.9% |
| ProofBench | 3% | — |
| Omni-MATH | — | 24.8% |
| LMArena Math | — | 1262 |
Knowledge Not comparable
Mercury 2.5: —, Mistral Small 3.1: 22.6 (#271)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| GPQA Diamond | — | 41.9% |
| MMLU-Pro | — | 61% |
| GPQA (HELM) | — | 39.2% |
| LMArena Expert | — | 1257 |
Multimodal Not comparable
Mercury 2.5: —, Mistral Small 3.1: 33.2 (#99)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | — | 1136 |
Multilingual Not comparable
Mercury 2.5: —, Mistral Small 3.1: 41.2 (#209)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | — | 1255 |
| LMArena Chinese | — | 1253 |
| LMArena French | — | 1273 |
| LMArena German | — | 1266 |
| LMArena Japanese | — | 1208 |
| LMArena Korean | — | 1206 |
| LMArena Russian | — | 1263 |
| LMArena Spanish | — | 1283 |
Instruction Following Not comparable
Mercury 2.5: —, Mistral Small 3.1: 63.6 (#230)
| 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 (#178)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | — | 1299 |
Writing & Preference Not comparable
Mercury 2.5: —, Mistral Small 3.1: 37.0 (#259)
| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | — | 1277 |
| 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?
Mercury 2.5 is the stronger model overall, scoring 33.5 to 31.7 on the Noometry Index.
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.
Is Mercury 2.5 or Mistral Small 3.1 better for coding?
Mercury 2.5 scores higher on coding benchmarks: 39.5 versus 38.3 in the Noometry coding category.
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 4 scored results on Noometry and Mistral Small 3.1 has 28.