# Claude Sonnet 5 vs Mistral Medium 3.5 128B

> Side-by-side benchmark comparison for Claude Sonnet 5 and Mistral Medium 3.5 128B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-vs-mistral-medium-3-5-128b
- Last updated: October 10, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Claude Sonnet 5 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Claude Sonnet 5 has the higher overall point estimate 65.92 to 34.72. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in agentic, where the averages are 64.8 for Claude Sonnet 5 and 19.2 for Mistral Medium 3.5 128B.
- The biggest single benchmark swing is GPQA Diamond (Vals) in Knowledge, with scores of 88.9% and 34.8%.
- Mistral Medium 3.5 128B is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Sonnet 5 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Sonnet 5 | Mistral Medium 3.5 128B |
|----------|----------|----------|
| Creator | Anthropic | Mistral |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Overall Score | 65.92 | 34.72 |
| Benchmarks Covered | 26 | 7 |
| Pricing (input/output) | $2.00 / $10.00 | $1.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Claude Sonnet 5
- Claude Sonnet 5 public-lane score: 64.8 (Supported · #16/123)
- Mistral Medium 3.5 128B public-lane score: 19.2 (Supported · #103/123)

| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.6% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 80.4% | Coming soon | Coming soon |
| BrowseComp | 84.7% | Coming soon | Coming soon |
| HLE w/ tools | 57.4% | Coming soon | Coming soon |
| OSWorld-Verified | 81.2% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 74.5% | 39.0% | Claude Sonnet 5 |
| ApprenticeBench | 16% | Coming soon | Coming soon |
| τ³-bench results | Coming soon | 91.4% | Coming soon |
| Gert Labs | Coming soon | 39.10% | Coming soon |

### Coding

- Winner: Directional only
- Claude Sonnet 5 public-lane score: 58.3 (Supported · #24/146)
- Mistral Medium 3.5 128B public-lane score: 23.6 (Estimated · #110/146)

| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85.2% | 77.6% | Claude Sonnet 5 |
| SWE-bench Pro | 63.2% | Coming soon | Coming soon |
| SWE Multilingual | 78.3% | Coming soon | Coming soon |
| SWE Multimodal | 28.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 80.4% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 42.7% | Coming soon | Coming soon |
| CursorBench 3.2 | 61.5% | Coming soon | Coming soon |
| VulcanBench CII v1 | 89.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 82.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 79.6% | 66.4% | Claude Sonnet 5 |
| CursorBench 4.0 | 34.1% | Coming soon | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Sonnet 5 public-lane score: 82.5 (Unranked · 2 rankable rows)
- Mistral Medium 3.5 128B public-lane score: 73.7 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Not comparable
- Claude Sonnet 5 public-lane score: 82 (#15/54)
- Mistral Medium 3.5 128B public-lane score: 60.1 (Unranked · 1 rankable row)

| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | 88.3% | Coming soon | Coming soon |
| CharXiv w/o tools | 77% | Coming soon | Coming soon |

### Knowledge

- Winner: Claude Sonnet 5
- Claude Sonnet 5 public-lane score: 65.6 (Supported · #29/177)
- Mistral Medium 3.5 128B public-lane score: 31.9 (Supported · #139/177)

| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.4% | Coming soon | Coming soon |
| HLE w/o tools | 43.2% | Coming soon | Coming soon |
| HLE-Verified | 31.0% | Coming soon | Coming soon |
| LABBench2 | 80.1% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 88.9% | 34.8% | Claude Sonnet 5 |
| MMLU-Pro (Vals) | 87.5% | 75.3% | Claude Sonnet 5 |

### Instruction Following

- Winner: Not comparable
- Claude Sonnet 5 public-lane score: Coming soon
- Mistral Medium 3.5 128B public-lane score: 84 (#50/127)

## FAQ

### Which is better overall, Claude Sonnet 5 or Mistral Medium 3.5 128B?

Claude Sonnet 5 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Claude Sonnet 5 and Mistral Medium 3.5 128B?

The widest category gap is in agentic, where the averages are 64.8 for Claude Sonnet 5 and 19.2 for Mistral Medium 3.5 128B.

### How many benchmarks does Claude Sonnet 5 cover on BenchLM?

Claude Sonnet 5 currently has 26 sourced benchmark scores on BenchLM.

### How many benchmarks does Mistral Medium 3.5 128B cover on BenchLM?

Mistral Medium 3.5 128B currently has 7 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-claude-sonnet-5)
- [Mistral Medium 3.5 128B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mistral-medium-3-5-128b)
- [Claude Sonnet 5 vs GPT-6 Astra](/compare/claude-sonnet-5-vs-gpt-6-astra)
- [Mistral Medium 3.5 128B vs GPT-6 Astra](/compare/gpt-6-astra-vs-mistral-medium-3-5-128b)

## Explore More

- [Claude Sonnet 5 profile](/models/claude-sonnet-5)
- [Mistral Medium 3.5 128B profile](/models/mistral-medium-3-5-128b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)