# Gemini 2.5 Flash vs Mistral Small 3.1

> Gemini 2.5 Flash is the stronger model overall, scoring 39.0 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 2.1× less per token, which makes it the better buy when Gemini 2.5 Flash's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-2-5-flash-vs-mistral-small-3-1
- Last updated: 2026-10-10
- Shared benchmarks: 26

## Summary

- They share 26 benchmarks with published results for both. Gemini 2.5 Flash scores higher in 7 categories and Mistral Small 3.1 in 2 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Gemini 2.5 Flash leads 38.1 to 13.7.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 73.1% for Gemini 2.5 Flash and 3.9% for Mistral Small 3.1.
- Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $0.30 / $2.50 for Gemini 2.5 Flash.
- Gemini 2.5 Flash accepts more context: 1.05M tokens versus 128K.
- Mistral Small 3.1 has downloadable open weights; the other is API-only.

## Snapshot

| | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| Provider | Google | Mistral AI |
| Noometry Index | 39.0 | 31.4 |
| Rank | 162 | 263 |
| Context | 1.05M | 128K |
| Input $/M | $0.30 | $0.35 |
| Output $/M | $2.50 | $0.56 |
| Weights | Proprietary | Open |

## Coding

- Gemini 2.5 Flash: 35.5 (#210)
- Mistral Small 3.1: 37.7 (#175)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | 1424 | 1309 |
| SWE-bench Verified (bash only) | 28.7% | — |
| Aider Polyglot | 55.1% | — |
| WeirdML | 41.9% | — |
| ALE-Bench | 661.88 | — |

## Agentic & Tool Use

- Gemini 2.5 Flash: 30.6 (#67)
- Mistral Small 3.1: —

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| Terminal-Bench | 17.1% | — |
| Berkeley Function Calling Leaderboard | 56.2% | — |
| TheAgentCompany | 41.1% | — |
| BALROG | 33.5% | — |
| Vending-Bench 2 | 548.84 | — |

## Reasoning

- Gemini 2.5 Flash: 18.2 (#271)
- Mistral Small 3.1: 18.9 (#249)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Hard Prompts | 1422 | 1278 |
| Epoch Capabilities Index | 143.04 | 127.48 |
| ARC-AGI-2 | 2.5% | — |
| SimpleBench | 41.2% | — |
| Kagi LLM Benchmark | 56.8% | — |
| ARC-AGI-1 | 33.3% | — |
| CritPt | 1.1% | — |
| Chess Puzzles | — | 1% |
| EnigmaEval | 2.7% | — |
| DTBench | 76.5% | — |
| LMCA | 27.5% | — |
| ForecastBench | 60.6 | — |

## Math

- Gemini 2.5 Flash: 38.1 (#87)
- Mistral Small 3.1: 13.7 (#295)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 73.1% | 3.9% |
| Omni-MATH | 38.5% | 24.8% |
| LMArena Math | 1415 | 1261 |
| FrontierMath (Feb 2025 set) | 4.8% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Gemini 2.5 Flash: 36.1 (#162)
- Mistral Small 3.1: 22.6 (#266)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| MMLU-Pro | 63.9% | 61% |
| GPQA (HELM) | 39% | 39.2% |
| LMArena Expert | 1426 | 1258 |
| GPQA Diamond | — | 41.9% |
| Humanity's Last Exam | 12.1% | — |
| Confabulations | 16.8% | — |
| Vectara Hallucination Rate | 7.8% | — |

## Multimodal

- Gemini 2.5 Flash: 41.2 (#31)
- Mistral Small 3.1: 32.6 (#93)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | 1254 | 1136 |
| GeoBench | 76% | — |
| VPCT | 46.2% | — |
| SpatialViz-Bench | 36.9% | — |

## Multilingual

- Gemini 2.5 Flash: 52.5 (#83)
- Mistral Small 3.1: 41.4 (#204)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | 1410 | 1255 |
| LMArena Chinese | 1450 | 1254 |
| LMArena French | 1433 | 1270 |
| LMArena German | 1419 | 1266 |
| LMArena Japanese | 1403 | 1210 |
| LMArena Korean | 1385 | 1206 |
| LMArena Russian | 1415 | 1263 |
| LMArena Spanish | 1421 | 1283 |

## Instruction Following

- Gemini 2.5 Flash: 75.9 (#50)
- Mistral Small 3.1: 63.8 (#225)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| IFEval | 89.8% | 75% |
| LMArena Instruction Following | 1405 | 1264 |

## Long Context

- Gemini 2.5 Flash: 47.5 (#16)
- Mistral Small 3.1: 39.5 (#172)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | 1419 | 1300 |
| Fiction.LiveBench | 77.8% | — |

## Writing & Preference

- Gemini 2.5 Flash: 54.0 (#153)
- Mistral Small 3.1: 37.2 (#254)

| Benchmark | Gemini 2.5 Flash | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | 1417 | 1278 |
| LMArena Creative Writing | 1400 | 1253 |
| EQ-Bench Creative Writing | 1137 | 761 |
| WildBench | 81.7% | 78.8% |
| LMArena Multi-Turn | 1408 | 1270 |
| Short-Story Creative Writing | 76.5% | — |

## FAQ

### Is Gemini 2.5 Flash better than Mistral Small 3.1?

Gemini 2.5 Flash is the stronger model overall, scoring 39.0 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 2.1× less per token, which makes it the better buy when Gemini 2.5 Flash's lead doesn't matter for your workload.

### Which is cheaper, Gemini 2.5 Flash or Mistral Small 3.1?

Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; Gemini 2.5 Flash lists at $0.30 and $2.50.

### Is Gemini 2.5 Flash or Mistral Small 3.1 better for coding?

Mistral Small 3.1 scores higher on coding benchmarks: 37.7 versus 35.5 in the Noometry coding category.

### Which has the bigger context window?

Gemini 2.5 Flash does, with 1.05M tokens against 128K.

### How many benchmarks do Gemini 2.5 Flash and Mistral Small 3.1 share?

26 benchmarks have published results for both models. Gemini 2.5 Flash has 54 scored results on Noometry and Mistral Small 3.1 has 28.