# Claude Opus 5.5 vs Mistral Medium

> Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 36.3 on the Noometry Index. Mistral Medium costs 2.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-5-5-vs-mistral-medium
- Last updated: 2026-10-10
- Shared benchmarks: 24

## Summary

- They share 24 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and Mistral Medium in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 5.5 leads 91.8 to 28.1.
- The biggest single-benchmark swing is ProofBench: 100% for Claude Opus 5.5 and 9% for Mistral Medium.
- Mistral Medium is cheaper at $1.50 / $7.50 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
- Claude Opus 5.5 accepts more context: 1M tokens versus 262K.
- Mistral Medium has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| Provider | Anthropic | Mistral AI |
| Noometry Index | 68.6 | 36.3 |
| Rank | 3 | 218 |
| Context | 1M | 262K |
| Input $/M | $4 | $1.50 |
| Output $/M | $20 | $7.50 |
| Weights | Proprietary | Open |

## Coding

- Claude Opus 5.5: 71.9 (#3)
- Mistral Medium: 34.2 (#243)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| FrontierCode | 54.6% | 8% |
| SciCode | 66.9% | 40.2% |
| LMArena Coding | 1547 | 1434 |
| ALE-Bench | 2,147 | 763.98 |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1813 | — |
| FrontierSWE | 62.3% | — |
| WeirdML | — | 43.7% |
| MirrorCode | 77.4% | — |

## Agentic & Tool Use

- Claude Opus 5.5: 45.3 (#15)
- Mistral Medium: 28.3 (#90)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| APEX-Agents | 73.5% | — |
| Berkeley Function Calling Leaderboard | — | 37.7% |
| GDP.pdf | 30.6% | — |
| Vending-Bench 2 | 9,235 | — |

## Reasoning

- Claude Opus 5.5: 80.2 (#3)
- Mistral Medium: 24.0 (#167)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| CritPt | 31.7% | 0% |
| LMArena Hard Prompts | 1535 | 1426 |
| DTBench | 98.9% | 75.5% |
| LMCA | 68.2% | 26.1% |
| ARC-AGI-2 | 93.3% | — |
| Kagi LLM Benchmark | — | 50% |
| NYT Connections (extended) | 88.5% | — |
| ARC-AGI-1 | 98.5% | — |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| Surface Evolver Bench | — | 26.9% |
| Epoch Capabilities Index | 167.33 | — |

## Math

- Claude Opus 5.5: 91.8 (#3)
- Mistral Medium: 28.1 (#245)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 32.2% |
| ProofBench | 100% | 9% |
| LMArena Math | 1506 | 1408 |
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| MATH Level 5 | — | 81.6% |
| FrontierMath (Feb 2025 set) | — | 0.3% |
| FrontierMath Erdős | 2.9% | — |

## Knowledge

- Claude Opus 5.5: 66.4 (#10)
- Mistral Medium: 25.0 (#265)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| GPQA Diamond | 90.6% | 59.5% |
| LMArena Expert | 1547 | 1408 |
| Humanity's Last Exam | — | 4.5% |
| SimpleQA Verified | 72.2% | — |
| Vectara Hallucination Rate | — | 22.7% |

## Multimodal

- Claude Opus 5.5: 57.8 (#1)
- Mistral Medium: 35.3 (#88)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| LMArena Vision | 1321 | 1172 |
| Blueprint-Bench 2 | 51.2% | — |
| Furniture Assembly | 83.3% | — |

## Multilingual

- Claude Opus 5.5: 59.1 (#2)
- Mistral Medium: 52.1 (#91)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| LMArena Non-English | 1507 | 1408 |
| LMArena Chinese | 1588 | 1447 |
| LMArena French | 1514 | 1459 |
| LMArena Russian | 1520 | 1411 |
| LMArena Spanish | 1507 | 1433 |
| LMArena German | — | 1432 |
| LMArena Japanese | — | 1378 |
| LMArena Korean | — | 1380 |

## Instruction Following

- Claude Opus 5.5: 80.0 (#3)
- Mistral Medium: 73.7 (#116)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| LMArena Instruction Following | 1537 | 1398 |

## Long Context

- Claude Opus 5.5: 47.1 (#19)
- Mistral Medium: 42.9 (#114)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| LMArena Longer Query | 1532 | 1406 |

## Writing & Preference

- Claude Opus 5.5: 78.2 (#3)
- Mistral Medium: 60.0 (#103)

| Benchmark | Claude Opus 5.5 | Mistral Medium |
|---|---|---|
| LMArena Text | 1515 | 1424 |
| LMArena Creative Writing | 1533 | 1391 |
| LMArena Multi-Turn | 1499 | 1418 |
| Short-Story Creative Writing | — | 77.3% |
| EQ-Bench Creative Writing | 2050 | — |

## FAQ

### Is Claude Opus 5.5 better than Mistral Medium?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 36.3 on the Noometry Index. Mistral Medium costs 2.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 5.5 or Mistral Medium?

Mistral Medium is cheaper. It lists at $1.50 per million input tokens and $7.50 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

### Is Claude Opus 5.5 or Mistral Medium better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 34.2 in the Noometry coding category.

### Which has the bigger context window?

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

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

24 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Mistral Medium has 36.