Model comparison

gpt-oss-120b vs Qwen3.5-Flash

Qwen3.5-Flash is the stronger model overall, scoring 42.3 to 36.0 on the Noometry Index. gpt-oss-120b costs 2.5× less per token, which makes it the better buy when Qwen3.5-Flash's lead doesn't matter for your workload.

Last verified . 27 shared benchmarks.

gpt-oss-120b OpenAI

36.0

Rank #210 Confirmed

Qwen3.5-Flash Alibaba (Qwen)

42.3

Rank #105 Confirmed

Summary

  • They share 27 benchmarks with published results for both. gpt-oss-120b scores higher in 1 category and Qwen3.5-Flash in 7 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in math, where gpt-oss-120b leads 50.6 to 36.3.
  • The biggest single-benchmark swing is Mystery Game Puzzles: 2% for gpt-oss-120b and 20% for Qwen3.5-Flash.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $0.10 / $0.40 for Qwen3.5-Flash.
  • Qwen3.5-Flash accepts more context: 1M tokens versus 131K.
  • gpt-oss-120b has downloadable open weights; the other is API-only.

Side by side

gpt-oss-120b and Qwen3.5-Flash specifications
gpt-oss-120bQwen3.5-Flash
ProviderOpenAIAlibaba (Qwen)
Noometry Index36.042.3
Released2025-08-052026-02-23
WeightsOpenProprietary
Context window131K1M
Max output41K66K
Input $ / M tokens$0.037$0.10
Output $ / M tokens$0.17$0.40
Results tracked4832

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Too close to call

gpt-oss-120b: 33.2 (#251), Qwen3.5-Flash: 33.9 (#234)

Coding benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
LMArena Coding13801412
ALE-Bench575.62221.8
SWE-bench Verified (bash only)26%—
Aider Polyglot41.8%—
LMArena WebDev—1243
SciCode36%—
WeirdML48.2%—
AlgoTune1.41—

Agentic & Tool Use Not comparable

gpt-oss-120b: 12.1 (#145), Qwen3.5-Flash: —

Agentic & Tool Use benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
Vending-Bench 2-21.53462.69
Terminal-Bench18.7%—
APEX-Agents4.4%—
METR Time Horizons56.6%—

Reasoning Qwen3.5-Flash leads

gpt-oss-120b: 19.5 (#236), Qwen3.5-Flash: 32.9 (#63)

Reasoning benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
Chess Puzzles20%21%
LMArena Hard Prompts13641404
Mystery Game Puzzles2%20%
DTBench76.3%82.9%
LMCA22.1%29.1%
Epoch Capabilities Index139.94143.98
SimpleBench22.1%—
Kagi LLM Benchmark58.6%—
CritPt1.1%—
Surface Evolver Bench25%—

Math gpt-oss-120b leads

gpt-oss-120b: 50.6 (#43), Qwen3.5-Flash: 36.3 (#117)

Math benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
OTIS Mock AIME 2024-202588.9%84.4%
LMArena Math13881407
FrontierMath (Tiers 1-3)—18.2%
Omni-MATH68.8%—
FrontierMath (Feb 2025 set)—6.2%
FrontierMath Tier 4 (v1)—0%

Knowledge Too close to call

gpt-oss-120b: 42.3 (#89), Qwen3.5-Flash: 43.2 (#84)

Knowledge benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
GPQA Diamond75.8%82.3%
Vectara Hallucination Rate14.2%10.5%
LMArena Expert13561408
SimpleQA Verified—20.3%
MMLU-Pro79.5%—
Confabulations15.7%—
GPQA (HELM)68.4%—

Multilingual Qwen3.5-Flash leads

gpt-oss-120b: 48.2 (#142), Qwen3.5-Flash: 50.7 (#116)

Multilingual benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
LMArena Non-English13501385
LMArena Chinese13841446
LMArena French13701412
LMArena German13551389
LMArena Japanese13321369
LMArena Korean12831344
LMArena Russian13431379
LMArena Spanish13881399

Instruction Following Qwen3.5-Flash leads

gpt-oss-120b: 69.5 (#168), Qwen3.5-Flash: 72.8 (#133)

Instruction Following benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
LMArena Instruction Following13181374
IFEval83.6%—

Long Context Qwen3.5-Flash leads

gpt-oss-120b: 31.4 (#273), Qwen3.5-Flash: 42.4 (#119)

Long Context benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
LMArena Longer Query13191392
Fiction.LiveBench44.4%—

Writing & Preference Qwen3.5-Flash leads

gpt-oss-120b: 46.7 (#213), Qwen3.5-Flash: 58.2 (#117)

Writing & Preference benchmarks
Benchmarkgpt-oss-120bQwen3.5-Flash
LMArena Text13661397
LMArena Creative Writing12741343
LMArena Multi-Turn13401393
Short-Story Creative Writing77.1%—
EQ-Bench Creative Writing961—
WildBench84.5%—

Frequently asked questions

Is gpt-oss-120b better than Qwen3.5-Flash?

Qwen3.5-Flash is the stronger model overall, scoring 42.3 to 36.0 on the Noometry Index. gpt-oss-120b costs 2.5× less per token, which makes it the better buy when Qwen3.5-Flash's lead doesn't matter for your workload.

Which is cheaper, gpt-oss-120b or Qwen3.5-Flash?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Qwen3.5-Flash lists at $0.10 and $0.40.

Is gpt-oss-120b or Qwen3.5-Flash better for coding?

They score almost the same on coding (33.2 vs 33.9); test both on your own repository before choosing.

Which has the bigger context window?

Qwen3.5-Flash does, with 1M tokens against 131K.

How many benchmarks do gpt-oss-120b and Qwen3.5-Flash share?

27 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Qwen3.5-Flash has 32.

Related comparisons

Go deeper