GPT-OSS 20B vs Qwen3.5 397B

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

Quick Verdict

Qwen3.5 397B wins overall with a score of 65 vs 22 (43 point difference).Qwen3.5 397B wins 4 out of 4 categories.

Knowledge

Qwen3.5 397B

GPT-OSS 20B

28.8

Qwen3.5 397B

80.8

31
MMLU
83
30
GPQA
82
28
SuperGPQA
80
26
OpenBookQA
78

Coding

Qwen3.5 397B

GPT-OSS 20B

23

Qwen3.5 397B

75

23
HumanEval
75

Mathematics

Qwen3.5 397B

GPT-OSS 20B

30

Qwen3.5 397B

82

31
AIME 2023
83
33
AIME 2024
85
32
AIME 2025
84
27
HMMT Feb 2023
79
29
HMMT Feb 2024
81
28
HMMT Feb 2025
80
30
BRUMO 2025
82

Reasoning

Qwen3.5 397B

GPT-OSS 20B

28

Qwen3.5 397B

79

29
SimpleQA
80
27
MuSR
78

Frequently Asked Questions

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

Qwen3.5 397B scores higher overall with 65 vs 22, a difference of 43 points across all benchmarks.

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

Qwen3.5 397B leads in knowledge tasks with an average score of 80.8 vs 28.8.

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

Qwen3.5 397B leads in coding with an average score of 75 vs 23.

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

Qwen3.5 397B leads in math with an average score of 82 vs 30.

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

Qwen3.5 397B leads in reasoning with an average score of 79 vs 28.