# 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.

- Canonical page: https://noometry.com/compare/mercury-2-5-vs-mistral-small-3-1
- Last updated: 2026-10-12
- Shared benchmarks: 0

## Summary

- 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.

## Snapshot

| | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| Provider | Inception | Mistral AI |
| Noometry Index | 33.5 | 31.7 |
| Rank | 242 | 269 |
| Context | 260K | 128K |
| Input $/M | $0.04 | $0.35 |
| Output $/M | $0.15 | $0.56 |
| Weights | Proprietary | Open |

## Coding

- 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: 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: 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

- 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

- Mercury 2.5: —
- Mistral Small 3.1: 33.2 (#99)

| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | — | 1136 |

## Multilingual

- 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

- 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

- Mercury 2.5: —
- Mistral Small 3.1: 39.5 (#178)

| Benchmark | Mercury 2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | — | 1299 |

## Writing & Preference

- 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 |

## FAQ

### 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.