# GPT-5 Mini vs Mistral Small 3.1

> GPT-5 Mini is the stronger model overall, scoring 41.7 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 1.7× less per token, which makes it the better buy when GPT-5 Mini's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-mini-vs-mistral-small-3-1
- Last updated: 2026-10-10
- Shared benchmarks: 28

## Summary

- They share 28 benchmarks with published results for both. GPT-5 Mini scores higher in 9 categories and Mistral Small 3.1 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5 Mini leads 46.3 to 13.7.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 86.7% for GPT-5 Mini 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 $0.25 / $2 for GPT-5 Mini.
- GPT-5 Mini accepts more context: 400K tokens versus 128K.
- Mistral Small 3.1 has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 41.7 | 31.4 |
| Rank | 115 | 263 |
| Context | 400K | 128K |
| Input $/M | $0.25 | $0.35 |
| Output $/M | $2 | $0.56 |
| Weights | Proprietary | Open |

## Coding

- GPT-5 Mini: 40.0 (#134)
- Mistral Small 3.1: 37.7 (#175)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | 1406 | 1309 |
| SWE-bench Verified | 64.7% | — |
| SWE-bench Verified (bash only) | 59.8% | — |
| SWE-bench Multilingual | 39.7% | — |
| SciCode | 39.2% | — |
| WeirdML | 52.7% | — |
| ALE-Bench | 799.77 | — |
| AlgoTune | 1.38 | — |

## Agentic & Tool Use

- GPT-5 Mini: 31.0 (#64)
- Mistral Small 3.1: —

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| Terminal-Bench | 34.8% | — |
| Berkeley Function Calling Leaderboard | 55.5% | — |
| Vending-Bench 2 | -31.18 | — |

## Reasoning

- GPT-5 Mini: 24.1 (#153)
- Mistral Small 3.1: 18.9 (#249)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| Chess Puzzles | 30% | 1% |
| LMArena Hard Prompts | 1380 | 1278 |
| Epoch Capabilities Index | 145.51 | 127.48 |
| ARC-AGI-2 | 4.4% | — |
| Kagi LLM Benchmark | 70.3% | — |
| ARC-AGI-1 | 54.3% | — |
| CritPt | 0% | — |
| EnigmaEval | 8.2% | — |
| Mystery Game Puzzles | 10% | — |
| DTBench | 80.5% | — |
| LMCA | 34.2% | — |
| ForecastBench | 61 | — |

## Math

- GPT-5 Mini: 46.3 (#59)
- Mistral Small 3.1: 13.7 (#295)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 86.7% | 3.9% |
| Omni-MATH | 72.2% | 24.8% |
| LMArena Math | 1377 | 1261 |
| FrontierMath (Tiers 1-3) | 46.7% | — |
| FrontierMath Tier 4 | 12.2% | — |
| ProofBench | 9% | — |
| MATH Level 5 | 97.8% | — |
| FrontierMath (Feb 2025 set) | 27.2% | — |
| FrontierMath Tier 4 (v1) | 6.3% | — |

## Knowledge

- GPT-5 Mini: 45.5 (#80)
- Mistral Small 3.1: 22.6 (#266)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| GPQA Diamond | 75% | 41.9% |
| MMLU-Pro | 83.5% | 61% |
| GPQA (HELM) | 75.6% | 39.2% |
| LMArena Expert | 1377 | 1258 |
| Humanity's Last Exam | 19.4% | — |
| SimpleQA Verified | 21.6% | — |
| Confabulations | 13.3% | — |
| Vectara Hallucination Rate | 12.9% | — |

## Multimodal

- GPT-5 Mini: 35.0 (#80)
- Mistral Small 3.1: 32.6 (#93)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | 1202 | 1136 |
| VPCT | 40.2% | — |

## Multilingual

- GPT-5 Mini: 49.1 (#131)
- Mistral Small 3.1: 41.4 (#204)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | 1363 | 1255 |
| LMArena Chinese | 1387 | 1254 |
| LMArena French | 1385 | 1270 |
| LMArena German | 1366 | 1266 |
| LMArena Japanese | 1342 | 1210 |
| LMArena Korean | 1306 | 1206 |
| LMArena Russian | 1362 | 1263 |
| LMArena Spanish | 1355 | 1283 |

## Instruction Following

- GPT-5 Mini: 76.4 (#43)
- Mistral Small 3.1: 63.8 (#225)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| IFEval | 92.7% | 75% |
| LMArena Instruction Following | 1357 | 1264 |

## Long Context

- GPT-5 Mini: 41.9 (#127)
- Mistral Small 3.1: 39.5 (#172)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | 1355 | 1300 |
| Fiction.LiveBench | 69.4% | — |

## Writing & Preference

- GPT-5 Mini: 55.4 (#143)
- Mistral Small 3.1: 37.2 (#254)

| Benchmark | GPT-5 Mini | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | 1373 | 1278 |
| LMArena Creative Writing | 1325 | 1253 |
| EQ-Bench Creative Writing | 1313 | 761 |
| WildBench | 85.5% | 78.8% |
| LMArena Multi-Turn | 1363 | 1270 |
| Short-Story Creative Writing | 83.1% | — |

## FAQ

### Is GPT-5 Mini better than Mistral Small 3.1?

GPT-5 Mini is the stronger model overall, scoring 41.7 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 1.7× less per token, which makes it the better buy when GPT-5 Mini's lead doesn't matter for your workload.

### Which is cheaper, GPT-5 Mini 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; GPT-5 Mini lists at $0.25 and $2.

### Is GPT-5 Mini or Mistral Small 3.1 better for coding?

GPT-5 Mini scores higher on coding benchmarks: 40.0 versus 37.7 in the Noometry coding category.

### Which has the bigger context window?

GPT-5 Mini does, with 400K tokens against 128K.

### How many benchmarks do GPT-5 Mini and Mistral Small 3.1 share?

28 benchmarks have published results for both models. GPT-5 Mini has 60 scored results on Noometry and Mistral Small 3.1 has 28.