benchlm.ai

Claude Opus 4.6 vs GPT-OSS 20B

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

Quick Verdict

Claude Opus 4.6 wins overall with a score of 86 vs 22 (64 point difference).Claude Opus 4.6 wins 4 out of 4 categories.

Claude Opus 4.6

CreatorAnthropic
TypeProprietary
Context1M
Score86

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Knowledge

Claude Opus 4.6

Claude Opus 4.6

96

GPT-OSS 20B

28.8

99
MMLU
31
97
GPQA
30
95
SuperGPQA
28
93
OpenBookQA
26

Coding

Claude Opus 4.6

Claude Opus 4.6

91

GPT-OSS 20B

23

91
HumanEval
23

Mathematics

Claude Opus 4.6

Claude Opus 4.6

97.1

GPT-OSS 20B

30

99
AIME 2023
31
99
AIME 2024
33
98
AIME 2025
32
95
HMMT Feb 2023
27
97
HMMT Feb 2024
29
96
HMMT Feb 2025
28
96
BRUMO 2025
30

Reasoning

Claude Opus 4.6

Claude Opus 4.6

94

GPT-OSS 20B

28

95
SimpleQA
29
93
MuSR
27

Frequently Asked Questions

Which is better, Claude Opus 4.6 or GPT-OSS 20B?

Claude Opus 4.6 scores higher overall with 86 vs 22, a difference of 64 points across all benchmarks.

Which is better for knowledge tasks, Claude Opus 4.6 or GPT-OSS 20B?

Claude Opus 4.6 leads in knowledge tasks with an average score of 96 vs 28.8.

Which is better for coding, Claude Opus 4.6 or GPT-OSS 20B?

Claude Opus 4.6 leads in coding with an average score of 91 vs 23.

Which is better for math, Claude Opus 4.6 or GPT-OSS 20B?

Claude Opus 4.6 leads in math with an average score of 97.1 vs 30.

Which is better for reasoning, Claude Opus 4.6 or GPT-OSS 20B?

Claude Opus 4.6 leads in reasoning with an average score of 94 vs 28.

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