Model comparison
Claude Opus 5 vs Mistral Medium 3.5 128B
Head-to-head evidence from 15 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 5 #1 (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 Opus 5 and Mistral Medium 3.5 128B share 15 comparable benchmark results. 1 of 8 categories are comparable. 64 results are unique to Claude Opus 5; 8 to Mistral Medium 3.5 128B.
Updated July 24, 2026- Shared results
- 15
- Claude Opus 5 only
- 64
- Mistral Medium 3.5 128B only
- 8
- Comparable categories
- 1 / 8
Treat this as a split decision. Claude Opus 5 makes more sense if coding is the priority; Mistral Medium 3.5 128B is the better fit if you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 15 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 Opus 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 Opus 5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $1.50 input / $7.50 output per 1M tokens for Mistral Medium 3.5 128B. That is roughly 3.3x on output cost alone.
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 Opus 5 | Δ | Mistral Medium 3.5 128B |
|---|---|---|---|
| Coding | Claude Opus 589.5 | Margin← 11.9 | Mistral Medium 3.5 128B77.6 |
| Agentic | Claude Opus 590.8 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Reasoning | Claude Opus 590.4 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Knowledge | Claude Opus 564.7 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Multimodal | Claude Opus 566.9 | 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 96%B 77.6%Winner: Claude Opus 5Δ 18.4SWE-bench Verified: Claude Opus 5 scored 96%; Mistral Medium 3.5 128B scored 77.6%. Claude Opus 5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 5 | Mistral Medium 3.5 128B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 5$5 input / $25 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 Opus 5Not available | Mistral Medium 3.5 128BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Opus 5Not available | Mistral Medium 3.5 128BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Opus 5Not available | Mistral Medium 3.5 128B256K | A complete context comparison is not available. |
Benchmark Deep Dive
Agentic30 benchmarks
| Benchmark | Claude Opus 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| FrontierBench v0.1Source | 43.3% | — | Not comparable |
| BrowseCompSource | 90.8% | — | Not comparable |
| HLE w/ toolsSource | 64.7% | — | Not comparable |
| DeepSearchQASource | 95.0% | — | Not comparable |
| DRACOSource | 88.6% | — | Not comparable |
| BrowseComp (10-agent, prerelease)Source | 93.6% | — | Not comparable |
| OSWorld 2.0Source | 70.6% | — | Not comparable |
| MCP AtlasSource | 85.8% | — | Not comparable |
| MCP-Atlas claim coverageSource | 89.1% | — | Not comparable |
| LAB all-pass (Anthropic harness)Source | 23.58% | — | Not comparable |
| LAB criterion-pass (Anthropic harness)Source | 93.74% | — | Not comparable |
| LAB all-pass (Harvey held-out)Source | 11.7% | — | Not comparable |
| LAB criterion-pass (Harvey held-out)Source | 94.1% | — | Not comparable |
| GDPval-AASource | 1861 | 933 | Claude Opus 5 leads |
| Toolathlon-VerifiedSource | 80.6% | — | Not comparable |
| Toolathlon Verified Pass@3Source | 87.0% | — | Not comparable |
| Toolathlon Verified Pass³Source | 73.1% | — | Not comparable |
| Toolathlon Verified avg. turnsSource | 23.5 turns | — | Not comparable |
| AutomationBenchSource | 26.0% | — | Not comparable |
| AA Agentic IndexSource | 55.3% | 19.0% | Claude Opus 5 leads |
| GDPval-AASource | 68.0% | 21.6% | Claude Opus 5 leads |
| AA Tau3 BankingSource | 30.3% | — | Not comparable |
| AA BriefcaseSource | 1720 | — | Not comparable |
| aaTerminalBench21Source | 89.1% | — | Not comparable |
| τ³-bench resultsSource | — | 91.4% | Not comparable |
| τ²-bench resultsSource | — | 94.2% | Not comparable |
| Gert LabsSource | — | 39.10% | Not comparable |
| AA EnterpriseOps-GymSource | — | 33.7% | Not comparable |
| AA Harvey LABSource | — | 69.1% | Not comparable |
| terminalBenchHardSource | — | 33.3% | Not comparable |
CodingClaude Opus 5 wins12 benchmarks
| Benchmark | Claude Opus 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 96% | 77.6% | Claude Opus 5 leads |
| SWE-bench ProSource | 79.2% | — | Not comparable |
| SWE MultilingualSource | 89.5% | — | Not comparable |
| SWE MultimodalSource | 59.4% | — | Not comparable |
| deepSweSource | 68.8% | — | Not comparable |
| FrontierCode 1.1 MainSource | 53.4% | — | Not comparable |
| FrontierCode 1.1 ExtendedSource | 63.6% | — | Not comparable |
| ProgramBench (episode 1)Source | 83.0% | — | Not comparable |
| ProgramBenchSource | 93.0% | — | Not comparable |
| cursorBench32Source | 70.0% | — | Not comparable |
| AA Coding IndexSource | 78.0% | 46.9% | Claude Opus 5 leads |
| AA-SciCodeSource | 55.7% | 39.6% | Claude Opus 5 leads |
Reasoning5 benchmarks
Knowledge22 benchmarks
| Benchmark | Claude Opus 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| HLESource | 64.7% | — | Not comparable |
| HLE w/o toolsSource | 56.3% | — | Not comparable |
| HealthBench (raw)Source | 67.1% | — | Not comparable |
| HealthBench (length-adjusted)Source | 57.8% | — | Not comparable |
| HealthBench ProfessionalSource | 59.8% | — | Not comparable |
| HealthBench Professional (raw)Source | 73.4% | — | Not comparable |
| BioMysteryBench (human-solvable)Source | 90.1% | — | Not comparable |
| BioMysteryBench (human-difficult)Source | 49.4% | — | Not comparable |
| SpatialBench VerifiedSource | 72.5% | — | Not comparable |
| SingleCellBenchSource | 60.6% | — | Not comparable |
| ProteinGym HardSource | 47.7% | — | Not comparable |
| Protein DesignSource | 42.5% | — | Not comparable |
| Organic chemistry V2Source | 61.6% | — | Not comparable |
| Protocols (troubleshooting)Source | 61.1% | — | Not comparable |
| Protocols (understanding)Source | 78.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 60.7% | 29.9% | Claude Opus 5 leads |
| AA-GPQA DiamondSource | 93.2% | 74.8% | Claude Opus 5 leads |
| AA-HLESource | 52.6% | 12.8% | Claude Opus 5 leads |
| AA-Omniscience IndexSource | 31.3% | -36.3% | Claude Opus 5 leads |
| AA-Omniscience AccuracySource | 54.2% | 25.1% | Claude Opus 5 leads |
| AA-Omniscience Hallucination RateSource | 50.1% | 82.0% | Claude Opus 5 leads |
| AA Openness IndexSource | — | 33.3% | Not comparable |
Math5 benchmarks
Multilingual3 benchmarks
Multimodal9 benchmarks
| Benchmark | Claude Opus 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| Chartography (no tools)Source | 29.6% | — | Not comparable |
| Chartography (tools)Source | 83.0% | — | Not comparable |
| BenchCAD Vision2Code (no tools)Source | 0.366 | — | Not comparable |
| BenchCAD Vision2Code (tools)Source | 0.821 | — | Not comparable |
| GDP.pdf (no tools)Source | 83.4% | — | Not comparable |
| GDP.pdf (tools)Source | 85.5% | — | Not comparable |
| OfficeQASource | 78.1% | — | Not comparable |
| OfficeQA ProSource | 66.9% | — | Not comparable |
| AA-MMMU-ProSource | 84.7% | 64.9% | Claude Opus 5 leads |
Inst. Following1 benchmarks
| Benchmark | Claude Opus 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 68.8% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude Opus 5 or Mistral Medium 3.5 128B?
Claude Opus 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 Opus 5 or Mistral Medium 3.5 128B?
Claude Opus 5 has the edge for coding in this comparison, averaging 89.5 versus 77.6. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.