Noometry

Model comparison

Claude Sonnet 5.5 vs Qwen3.5-Flash

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 42.5 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 . 20 shared benchmarks.

Claude Sonnet 5.5 Anthropic

61.9

Rank #10 Confirmed

Qwen3.5-Flash Alibaba (Qwen)

42.5

Rank #112 Confirmed

Summary

  • They share 20 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 8 categories and Qwen3.5-Flash in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 37.4.
  • 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 5.5Qwen3.5-Flash
ProviderAnthropicAlibaba (Qwen)
Noometry Index61.942.5
Released2026-09-282026-02-23
WeightsProprietaryProprietary
Context window1M1M
Max output128K66K
Input $ / M tokens$2$0.10
Output $ / M tokens$10$0.40
Results tracked3232

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 67.3 (#6), Qwen3.5-Flash: 34.2 (#242)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena WebDev17741244
LMArena Coding15131412
ALE-Bench1,819221.8
FrontierCode52.1%—
CursorBench55.5%—
FrontierSWE61.9%—
SciCode61%—

Agentic & Tool Use Not comparable

Claude Sonnet 5.5: 45.0 (#16), Qwen3.5-Flash: —

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
APEX-Agents75.5%—
Vending-Bench 2—462.69

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 54.0 (#28), Qwen3.5-Flash: 33.7 (#72)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Hard Prompts14951403
Mystery Game Puzzles65%20%
Epoch Capabilities Index165.03143.98
NYT Connections (extended)80.5%—
CritPt31.4%—
Chess Puzzles—21%
DTBench—82.9%
LMCA—29.1%

Math Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 87.9 (#6), Qwen3.5-Flash: 37.4 (#158)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
FrontierMath (Tiers 1-3)88.8%18.2%
OTIS Mock AIME 2024-2025100%84.4%
LMArena Math15101407
FrontierMath Tier 480.5%—
ProofBench100%—
FrontierMath (Feb 2025 set)—6.2%
FrontierMath Erdős2.9%—
FrontierMath Tier 4 (v1)—0%

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#12), Qwen3.5-Flash: 43.2 (#93)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
GPQA Diamond95.6%82.3%
SimpleQA Verified46.5%20.3%
LMArena Expert15401407
Vectara Hallucination Rate—10.5%

Multimodal Not comparable

Claude Sonnet 5.5: 51.5 (#6), Qwen3.5-Flash: —

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Vision1289—
Furniture Assembly75%—

Multilingual Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 55.3 (#30), Qwen3.5-Flash: 50.5 (#121)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Non-English14521385
LMArena Chinese15221446
LMArena Russian14511379
LMArena French—1412
LMArena German—1390
LMArena Japanese—1368
LMArena Korean—1344
LMArena Spanish—1400

Instruction Following Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 78.3 (#11), Qwen3.5-Flash: 72.6 (#139)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Instruction Following14951374

Long Context Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.9 (#28), Qwen3.5-Flash: 42.4 (#124)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Longer Query14981392

Writing & Preference Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#40), Qwen3.5-Flash: 57.9 (#122)

BenchmarkClaude Sonnet 5.5Qwen3.5-Flash
LMArena Text14711397
LMArena Creative Writing14651343
LMArena Multi-Turn14741393

Frequently asked questions

Is Claude Sonnet 5.5 better than Qwen3.5-Flash?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 42.5 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: 67.3 versus 34.2 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?

20 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Qwen3.5-Flash has 32.

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