Model comparison
Claude Sonnet 5 vs Mistral Medium 3.5 128B
Head-to-head evidence from 19 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Sonnet 5 #29 (Estimated); Mistral Medium 3.5 128B unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 5 and Mistral Medium 3.5 128B share 19 comparable benchmark results. 1 of 8 categories are comparable. 17 results are unique to Claude Sonnet 5; 6 to Mistral Medium 3.5 128B.
Updated July 23, 2026- Shared results
- 19
- Claude Sonnet 5 only
- 17
- Mistral Medium 3.5 128B only
- 6
- Comparable categories
- 1 / 8
Treat this as a split decision. Claude Sonnet 5 makes more sense if you need the larger 1M context window; Mistral Medium 3.5 128B is the better fit if coding is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 19 shared benchmark results across 5 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Claude Sonnet 5 and Mistral Medium 3.5 128B finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Claude Sonnet 5 is also the more expensive model on tokens at $2.00 input / $10.00 output per 1M tokens, versus $1.50 input / $7.50 output per 1M tokens for Mistral Medium 3.5 128B. Claude Sonnet 5 gives you the larger context window at 1M, compared with 256K for Mistral Medium 3.5 128B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Claude Sonnet 5 | Δ | Mistral Medium 3.5 128B |
|---|---|---|---|
| Coding | Claude Sonnet 576.7 | Margin→ 0.9 | Mistral Medium 3.5 128B77.6 |
| Agentic | Claude Sonnet 581.9 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Knowledge | Claude Sonnet 557.4 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Multimodal | Claude Sonnet 588.3 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 85.2%B 77.6%Winner: Claude Sonnet 5Δ 7.6SWE-bench Verified: Claude Sonnet 5 scored 85.2%; Mistral Medium 3.5 128B scored 77.6%. Claude Sonnet 5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 5 | Mistral Medium 3.5 128B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 5$2 input / $10 output | Mistral Medium 3.5 128B$1.5 input / $7.5 output | Mistral Medium 3.5 128B has the lower combined listed price. |
| Generation speedtokens per second | Claude Sonnet 5Not available | Mistral Medium 3.5 128BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 5Not available | Mistral Medium 3.5 128BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 51M | Mistral Medium 3.5 128B256K | Claude Sonnet 5 lists the larger context window. |
Benchmark Deep Dive
Agentic17 benchmarks
| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 80.4% | — | Not comparable |
| BrowseCompSource | 84.7% | — | Not comparable |
| HLE w/ toolsSource | 57.4% | — | Not comparable |
| OSWorld-VerifiedSource | 81.2% | — | Not comparable |
| GDPval-AASource | 1607 | 929 | Claude Sonnet 5 leads |
| AA Agentic IndexSource | 46.7% | 19.0% | Claude Sonnet 5 leads |
| GDPval-AASource | 55.4% | 21.4% | Claude Sonnet 5 leads |
| AA BriefcaseSource | 1388 | 506 | Claude Sonnet 5 leads |
| AA AutomationBenchSource | 39.2% | — | Not comparable |
| AA EnterpriseOps-GymSource | 44.7% | 33.7% | Claude Sonnet 5 leads |
| AA Harvey LABSource | 90.1% | 69.1% | Claude Sonnet 5 leads |
| AA Tau3 BankingSource | 28.2% | 14.4% | Claude Sonnet 5 leads |
| aaTerminalBench21Source | 80.5% | — | Not comparable |
| τ³-bench resultsSource | — | 91.4% | Not comparable |
| τ²-bench resultsSource | — | 94.2% | Not comparable |
| Gert LabsSource | — | 39.10% | Not comparable |
| terminalBenchHardSource | — | 33.3% | Not comparable |
CodingMistral Medium 3.5 128B wins9 benchmarks
| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 85.2% | 77.6% | Claude Sonnet 5 leads |
| SWE-bench ProSource | 63.2% | — | Not comparable |
| SWE MultilingualSource | 78.3% | — | Not comparable |
| SWE MultimodalSource | 28.1% | — | Not comparable |
| Terminal-Bench 2.0Source | 80.4% | — | Not comparable |
| FrontierCode 1.1 MainSource | 42.7% | — | Not comparable |
| cursorBench32Source | 61.5% | — | Not comparable |
| AA Coding IndexSource | 71.5% | 46.9% | Claude Sonnet 5 leads |
| AA-SciCodeSource | 53.6% | 39.6% | Claude Sonnet 5 leads |
Reasoning2 benchmarks
Knowledge9 benchmarks
| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| HLESource | 57.4% | — | Not comparable |
| HLE w/o toolsSource | 43.2% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 53.4% | 29.9% | Claude Sonnet 5 leads |
| AA-GPQA DiamondSource | 91.1% | 74.8% | Claude Sonnet 5 leads |
| AA-HLESource | 39.6% | 12.8% | Claude Sonnet 5 leads |
| AA-Omniscience IndexSource | 15.3% | -36.3% | Claude Sonnet 5 leads |
| AA-Omniscience AccuracySource | 38.3% | 25.1% | Claude Sonnet 5 leads |
| AA-Omniscience Hallucination RateSource | 37.3% | 82.0% | Claude Sonnet 5 leads |
| AA Openness IndexSource | — | 33.3% | Not comparable |
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 68.8% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude Sonnet 5 or Mistral Medium 3.5 128B?
Claude Sonnet 5 and Mistral Medium 3.5 128B are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, Claude Sonnet 5 or Mistral Medium 3.5 128B?
Mistral Medium 3.5 128B has the edge for coding in this comparison, averaging 77.6 versus 76.7. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.
Related Comparisons
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.