# Claude Sonnet 4.5 vs Qwen3.5-27B

> Side-by-side benchmark comparison for Claude Sonnet 4.5 and Qwen3.5-27B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-4-5-vs-qwen3-5-27b
- Last updated: September 28, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. Qwen3.5-27B only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 4.5 leads overall 47.86 to 43.76.
- The clearest category separation is in reasoning, where the averages are 19.2 for Claude Sonnet 4.5 and 52.7 for Qwen3.5-27B.
- The biggest single benchmark swing is Gert Labs in Agentic, with scores of 48.51% and 39.41%.
- Qwen3.5-27B is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Qwen3.5-27B also has the larger context window at 262K.

## Model Snapshot

| Property | Claude Sonnet 4.5 | Qwen3.5-27B |
|----------|----------|----------|
| Creator | Anthropic | Alibaba |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 262K |
| Overall Score | 47.86 | 43.76 |
| Benchmarks Covered | 11 | 16 |
| Pricing (input/output) | $3.00 / $15.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Claude Sonnet 4.5 public-lane score: 34.4 (Estimated · #68/117)
- Qwen3.5-27B public-lane score: 32.5 (Estimated · #74/117)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 50% | 41.6% | Claude Sonnet 4.5 |
| OSWorld-Verified | 61.4% | 56.2% | Claude Sonnet 4.5 |
| VITA-Bench | 17.0% | Coming soon | Coming soon |
| Gert Labs | 48.51% | 39.41% | Claude Sonnet 4.5 |
| JobBench | 27.7% | Coming soon | Coming soon |
| BrowseComp | Coming soon | 61% | Coming soon |

### Coding

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: Coming soon
- Qwen3.5-27B public-lane score: 32.4 (Estimated · #86/142)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 77.2% | 72.4% | Claude Sonnet 4.5 |
| SWE-Rebench | Coming soon | 58.9% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: 19.2 (Unranked · 1 rankable row)
- Qwen3.5-27B public-lane score: 52.7 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 13.6% | Coming soon | Coming soon |
| LongBench v2 | Coming soon | 60.6% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: Coming soon
- Qwen3.5-27B public-lane score: 71.6 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| MMMU | Coming soon | 82.3% | Coming soon |
| MMVU | Coming soon | 73.3% | Coming soon |
| MathVision | Coming soon | 86.0% | Coming soon |
| V* | Coming soon | 93.7% | Coming soon |

### Knowledge

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: Coming soon
- Qwen3.5-27B public-lane score: 42.3 (Supported · #87/168)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 83.4% | 85.5% | Qwen3.5-27B |
| MMLU-Pro | Coming soon | 86.1% | Coming soon |
| SuperGPQA | Coming soon | 65.6% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: Coming soon
- Qwen3.5-27B public-lane score: 36.8 (#9/12)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | Coming soon | 82.2% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: Coming soon
- Qwen3.5-27B public-lane score: 91.5 (#13/124)

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 95% | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Sonnet 4.5 public-lane score: 34.6 (Unranked · 2 rankable rows)
- Qwen3.5-27B public-lane score: Coming soon

| Benchmark | Claude Sonnet 4.5 | Qwen3.5-27B | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | 87% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 13.495% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 4.167% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 4.5 or Qwen3.5-27B?

Claude Sonnet 4.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 4.5 and Qwen3.5-27B?

The widest category gap is in reasoning, where the averages are 19.2 for Claude Sonnet 4.5 and 52.7 for Qwen3.5-27B.

### How many benchmarks does Claude Sonnet 4.5 cover on BenchLM?

Claude Sonnet 4.5 currently has 11 sourced benchmark scores on BenchLM.

### How many benchmarks does Qwen3.5-27B cover on BenchLM?

Qwen3.5-27B currently has 16 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 4.5 vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-vs-claude-sonnet-4-5-thinking)
- [Qwen3.5-27B vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-thinking-vs-qwen3-5-27b)
- [Claude Sonnet 4.5 vs GPT-6 Astra](/compare/claude-sonnet-4-5-vs-gpt-6-astra)
- [Qwen3.5-27B vs GPT-6 Astra](/compare/gpt-6-astra-vs-qwen3-5-27b)

## Explore More

- [Claude Sonnet 4.5 profile](/models/claude-sonnet-4-5)
- [Qwen3.5-27B profile](/models/qwen3-5-27b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)