Model comparison
Claude Sonnet 5.5 vs Qwen3.5-Flash
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 42.3 on the Noometry Index. Qwen3.5-Flash costs 23× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.
Last verified . 7 shared benchmarks.
Alibaba (Qwen)Summary
- They share 7 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 4 categories and Qwen3.5-Flash in 0 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 88.7 to 36.3.
- The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 88.8% for Claude Sonnet 5.5 and 18.2% for Qwen3.5-Flash.
- Qwen3.5-Flash is cheaper at $0.10 / $0.40 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
Side by side
| Claude Sonnet 5.5 | Qwen3.5-Flash | |
|---|---|---|
| Provider | Anthropic | Alibaba (Qwen) |
| Noometry Index | 60.5 | 42.3 |
| Released | 2026-09-28 | 2026-02-23 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 1M |
| Max output | 128K | 66K |
| Input $ / M tokens | $2 | $0.10 |
| Output $ / M tokens | $10 | $0.40 |
| Results tracked | 16 | 32 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 65.5 (#6), Qwen3.5-Flash: 33.9 (#234)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| LMArena WebDev | 1699 | 1243 |
| ALE-Bench | 1,819 | 221.8 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| LMArena Coding | — | 1412 |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 44.9 (#14), Qwen3.5-Flash: —
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| APEX-Agents | 75.5% | — |
| Vending-Bench 2 | — | 462.69 |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 52.4 (#29), Qwen3.5-Flash: 32.9 (#63)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| Mystery Game Puzzles | 65% | 20% |
| CritPt | 31.4% | — |
| Chess Puzzles | — | 21% |
| LMArena Hard Prompts | — | 1404 |
| DTBench | — | 82.9% |
| LMCA | — | 29.1% |
| Epoch Capabilities Index | — | 143.98 |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 88.7 (#4), Qwen3.5-Flash: 36.3 (#117)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | 18.2% |
| OTIS Mock AIME 2024-2025 | 100% | 84.4% |
| FrontierMath Tier 4 | 80.5% | — |
| ProofBench | 100% | — |
| LMArena Math | — | 1407 |
| FrontierMath (Feb 2025 set) | — | 6.2% |
| FrontierMath Tier 4 (v1) | — | 0% |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#11), Qwen3.5-Flash: 43.2 (#84)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| GPQA Diamond | 95.6% | 82.3% |
| SimpleQA Verified | 46.5% | 20.3% |
| Vectara Hallucination Rate | — | 10.5% |
| LMArena Expert | — | 1408 |
Multimodal Not comparable
Claude Sonnet 5.5: 53.2 (#5), Qwen3.5-Flash: —
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| Furniture Assembly | 75% | — |
Multilingual Not comparable
Claude Sonnet 5.5: —, Qwen3.5-Flash: 50.7 (#116)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| LMArena Non-English | — | 1385 |
| LMArena Chinese | — | 1446 |
| LMArena French | — | 1412 |
| LMArena German | — | 1389 |
| LMArena Japanese | — | 1369 |
| LMArena Korean | — | 1344 |
| LMArena Russian | — | 1379 |
| LMArena Spanish | — | 1399 |
Instruction Following Not comparable
Claude Sonnet 5.5: —, Qwen3.5-Flash: 72.8 (#133)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| LMArena Instruction Following | — | 1374 |
Long Context Not comparable
Claude Sonnet 5.5: —, Qwen3.5-Flash: 42.4 (#119)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| LMArena Longer Query | — | 1392 |
Writing & Preference Not comparable
Claude Sonnet 5.5: —, Qwen3.5-Flash: 58.2 (#117)
| Benchmark | Claude Sonnet 5.5 | Qwen3.5-Flash |
|---|---|---|
| LMArena Text | — | 1397 |
| LMArena Creative Writing | — | 1343 |
| LMArena Multi-Turn | — | 1393 |
Frequently asked questions
Is Claude Sonnet 5.5 better than Qwen3.5-Flash?
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 42.3 on the Noometry Index. Qwen3.5-Flash costs 23× 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 Qwen3.5-Flash?
Qwen3.5-Flash is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.
Is Claude Sonnet 5.5 or Qwen3.5-Flash better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 33.9 in the Noometry coding category.
Which has the bigger context window?
Both accept 1M tokens.
How many benchmarks do Claude Sonnet 5.5 and Qwen3.5-Flash share?
7 benchmarks have published results for both models. Claude Sonnet 5.5 has 16 scored results on Noometry and Qwen3.5-Flash has 32.