Model comparison
Claude Sonnet 5.5 vs Mistral Medium 3.1
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 31.9 on the Noometry Index. Mistral Medium 3.1 costs 5.0× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Last verified . 1 shared benchmarks.
Mistral AISummary
- They share 1 benchmark with published results for both. Claude Sonnet 5.5 scores higher in 2 categories and Mistral Medium 3.1 in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Sonnet 5.5 leads 54.0 to 10.6.
- The biggest single-benchmark swing is NYT Connections (extended): 80.5% for Claude Sonnet 5.5 and 6.5% for Mistral Medium 3.1.
- Mistral Medium 3.1 is cheaper at $0.40 / $2 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
- Claude Sonnet 5.5 accepts more context: 1M tokens versus 131K.
Side by side
| Claude Sonnet 5.5 | Mistral Medium 3.1 | |
|---|---|---|
| Provider | Anthropic | Mistral AI |
| Noometry Index | 61.9 | 31.9 |
| Released | 2026-09-28 | — |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 131K |
| Max output | 128K | 105K |
| Input $ / M tokens | $2 | $0.40 |
| Output $ / M tokens | $10 | $2 |
| Results tracked | 32 | 3 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Not comparable
Claude Sonnet 5.5: 67.3 (#6), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1774 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| LMArena Coding | 1513 | — |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 45.0 (#16), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| APEX-Agents | 75.5% | — |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 54.0 (#28), Mistral Medium 3.1: 10.6 (#341)
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| NYT Connections (extended) | 80.5% | 6.5% |
| CritPt | 31.4% | — |
| Thematic Generalization | — | 20.3% |
| LMArena Hard Prompts | 1495 | — |
| Mystery Game Puzzles | 65% | — |
| Epoch Capabilities Index | 165.03 | — |
Math Not comparable
Claude Sonnet 5.5: 87.9 (#6), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| LMArena Math | 1510 | — |
| FrontierMath Erdős | 2.9% | — |
Knowledge Not comparable
Claude Sonnet 5.5: 66.0 (#12), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| GPQA Diamond | 95.6% | — |
| SimpleQA Verified | 46.5% | — |
| LMArena Expert | 1540 | — |
Multimodal Not comparable
Claude Sonnet 5.5: 51.5 (#6), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| LMArena Vision | 1289 | — |
| Furniture Assembly | 75% | — |
Multilingual Not comparable
Claude Sonnet 5.5: 55.3 (#30), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| LMArena Non-English | 1452 | — |
| LMArena Chinese | 1522 | — |
| LMArena Russian | 1451 | — |
Instruction Following Not comparable
Claude Sonnet 5.5: 78.3 (#11), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| LMArena Instruction Following | 1495 | — |
Long Context Not comparable
Claude Sonnet 5.5: 45.9 (#28), Mistral Medium 3.1: —
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| LMArena Longer Query | 1498 | — |
Writing & Preference Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#40), Mistral Medium 3.1: 55.5 (#145)
| Benchmark | Claude Sonnet 5.5 | Mistral Medium 3.1 |
|---|---|---|
| LMArena Text | 1471 | — |
| LMArena Creative Writing | 1465 | — |
| EQ-Bench Creative Writing | — | 1476 |
| LMArena Multi-Turn | 1474 | — |
Frequently asked questions
Is Claude Sonnet 5.5 better than Mistral Medium 3.1?
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 31.9 on the Noometry Index. Mistral Medium 3.1 costs 5.0× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Sonnet 5.5 or Mistral Medium 3.1?
Mistral Medium 3.1 is cheaper. It lists at $0.40 per million input tokens and $2 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.
Which has the bigger context window?
Claude Sonnet 5.5 does, with 1M tokens against 131K.
How many benchmarks do Claude Sonnet 5.5 and Mistral Medium 3.1 share?
1 benchmark has published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Mistral Medium 3.1 has 3.