benchlm.ai

GPT-OSS 20B vs Qwen3.5 397B (Reasoning)

Side-by-side benchmark comparison across knowledge, coding, math, and reasoning.

Quick Verdict

Qwen3.5 397B (Reasoning) wins overall with a score of 70 vs 22 (48 point difference).Qwen3.5 397B (Reasoning) wins 4 out of 4 categories.

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Qwen3.5 397B (Reasoning)

CreatorAlibaba
TypeOpen Weight
Context128K
Score70

Knowledge

Qwen3.5 397B (Reasoning)

GPT-OSS 20B

28.8

Qwen3.5 397B (Reasoning)

88

31
MMLU
91
30
GPQA
89
28
SuperGPQA
87
26
OpenBookQA
85

Coding

Qwen3.5 397B (Reasoning)

GPT-OSS 20B

23

Qwen3.5 397B (Reasoning)

83

23
HumanEval
83

Mathematics

Qwen3.5 397B (Reasoning)

GPT-OSS 20B

30

Qwen3.5 397B (Reasoning)

92

31
AIME 2023
93
33
AIME 2024
95
32
AIME 2025
94
27
HMMT Feb 2023
89
29
HMMT Feb 2024
91
28
HMMT Feb 2025
90
30
BRUMO 2025
92

Reasoning

Qwen3.5 397B (Reasoning)

GPT-OSS 20B

28

Qwen3.5 397B (Reasoning)

86

29
SimpleQA
87
27
MuSR
85

Frequently Asked Questions

Which is better, GPT-OSS 20B or Qwen3.5 397B (Reasoning)?

Qwen3.5 397B (Reasoning) scores higher overall with 70 vs 22, a difference of 48 points across all benchmarks.

Which is better for knowledge tasks, GPT-OSS 20B or Qwen3.5 397B (Reasoning)?

Qwen3.5 397B (Reasoning) leads in knowledge tasks with an average score of 88 vs 28.8.

Which is better for coding, GPT-OSS 20B or Qwen3.5 397B (Reasoning)?

Qwen3.5 397B (Reasoning) leads in coding with an average score of 83 vs 23.

Which is better for math, GPT-OSS 20B or Qwen3.5 397B (Reasoning)?

Qwen3.5 397B (Reasoning) leads in math with an average score of 92 vs 30.

Which is better for reasoning, GPT-OSS 20B or Qwen3.5 397B (Reasoning)?

Qwen3.5 397B (Reasoning) leads in reasoning with an average score of 86 vs 28.

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