# Claude Sonnet 5.5 vs Mistral Medium 3.5

> Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 40.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-sonnet-5-5-vs-mistral-medium-3-5
- Last updated: 2026-10-12
- Shared benchmarks: 16

## Summary

- They share 16 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 9 categories and Mistral Medium 3.5 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 39.1.
- The biggest single-benchmark swing is NYT Connections (extended): 80.5% for Claude Sonnet 5.5 and 12.9% for Mistral Medium 3.5.
- Mistral Medium 3.5 is cheaper at $1.50 / $7.50 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
- Claude Sonnet 5.5 accepts more context: 1M tokens versus 262K.
- Mistral Medium 3.5 has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| Provider | Anthropic | Mistral AI |
| Noometry Index | 61.9 | 40.2 |
| Rank | 10 | 152 |
| Context | 1M | 262K |
| Input $/M | $2 | $1.50 |
| Output $/M | $10 | $7.50 |
| Weights | Proprietary | Open |

## Coding

- Claude Sonnet 5.5: 67.3 (#6)
- Mistral Medium 3.5: 36.0 (#213)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena WebDev | 1774 | 1264 |
| LMArena Coding | 1513 | 1461 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| ALE-Bench | 1,819 | — |

## Agentic & Tool Use

- Claude Sonnet 5.5: 45.0 (#16)
- Mistral Medium 3.5: —

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| APEX-Agents | 75.5% | — |

## Reasoning

- Claude Sonnet 5.5: 54.0 (#28)
- Mistral Medium 3.5: 17.3 (#295)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| NYT Connections (extended) | 80.5% | 12.9% |
| LMArena Hard Prompts | 1495 | 1436 |
| Epoch Capabilities Index | 165.03 | 141.35 |
| Kagi LLM Benchmark | — | 41.4% |
| CritPt | 31.4% | — |
| Mystery Game Puzzles | 65% | — |

## Math

- Claude Sonnet 5.5: 87.9 (#6)
- Mistral Medium 3.5: 39.1 (#113)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Math | 1510 | 1431 |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| FrontierMath Erdős | 2.9% | — |

## Knowledge

- Claude Sonnet 5.5: 66.0 (#12)
- Mistral Medium 3.5: 40.0 (#126)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Expert | 1540 | 1432 |
| GPQA Diamond | 95.6% | — |
| SimpleQA Verified | 46.5% | — |

## Multimodal

- Claude Sonnet 5.5: 51.5 (#6)
- Mistral Medium 3.5: 38.3 (#65)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Vision | 1289 | 1223 |
| Furniture Assembly | 75% | — |

## Multilingual

- Claude Sonnet 5.5: 55.3 (#30)
- Mistral Medium 3.5: 51.9 (#100)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Non-English | 1452 | 1404 |
| LMArena Chinese | 1522 | 1442 |
| LMArena Russian | 1451 | 1395 |
| LMArena French | — | 1448 |
| LMArena German | — | 1451 |
| LMArena Korean | — | 1385 |
| LMArena Spanish | — | 1409 |

## Instruction Following

- Claude Sonnet 5.5: 78.3 (#11)
- Mistral Medium 3.5: 74.6 (#90)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Instruction Following | 1495 | 1415 |

## Long Context

- Claude Sonnet 5.5: 45.9 (#28)
- Mistral Medium 3.5: 43.2 (#103)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Longer Query | 1498 | 1415 |

## Writing & Preference

- Claude Sonnet 5.5: 66.0 (#40)
- Mistral Medium 3.5: 58.5 (#117)

| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.5 |
|---|---|---|
| LMArena Text | 1471 | 1421 |
| LMArena Creative Writing | 1465 | 1374 |
| LMArena Multi-Turn | 1474 | 1423 |
| EQ-Bench 4 | — | 993 |

## FAQ

### Is Claude Sonnet 5.5 better than Mistral Medium 3.5?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 40.2 on the Noometry Index.

### Which is cheaper, Claude Sonnet 5.5 or Mistral Medium 3.5?

Mistral Medium 3.5 is cheaper. It lists at $1.50 per million input tokens and $7.50 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.

### Is Claude Sonnet 5.5 or Mistral Medium 3.5 better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 36.0 in the Noometry coding category.

### Which has the bigger context window?

Claude Sonnet 5.5 does, with 1M tokens against 262K.

### How many benchmarks do Claude Sonnet 5.5 and Mistral Medium 3.5 share?

16 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Mistral Medium 3.5 has 22.