benchlm.ai

Claude 4 Sonnet vs GPT-OSS 20B

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

Quick Verdict

Claude 4 Sonnet wins overall with a score of 59 vs 22 (37 point difference).Claude 4 Sonnet wins 4 out of 4 categories.

Claude 4 Sonnet

CreatorAnthropic
TypeProprietary
Context200K
Score59

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Knowledge

Claude 4 Sonnet

Claude 4 Sonnet

71.5

GPT-OSS 20B

28.8

73
MMLU
31
73
GPQA
30
71
SuperGPQA
28
69
OpenBookQA
26

Coding

Claude 4 Sonnet

Claude 4 Sonnet

65

GPT-OSS 20B

23

65
HumanEval
23

Mathematics

Claude 4 Sonnet

Claude 4 Sonnet

72

GPT-OSS 20B

30

73
AIME 2023
31
75
AIME 2024
33
74
AIME 2025
32
69
HMMT Feb 2023
27
71
HMMT Feb 2024
29
70
HMMT Feb 2025
28
72
BRUMO 2025
30

Reasoning

Claude 4 Sonnet

Claude 4 Sonnet

70

GPT-OSS 20B

28

71
SimpleQA
29
69
MuSR
27

Frequently Asked Questions

Which is better, Claude 4 Sonnet or GPT-OSS 20B?

Claude 4 Sonnet scores higher overall with 59 vs 22, a difference of 37 points across all benchmarks.

Which is better for knowledge tasks, Claude 4 Sonnet or GPT-OSS 20B?

Claude 4 Sonnet leads in knowledge tasks with an average score of 71.5 vs 28.8.

Which is better for coding, Claude 4 Sonnet or GPT-OSS 20B?

Claude 4 Sonnet leads in coding with an average score of 65 vs 23.

Which is better for math, Claude 4 Sonnet or GPT-OSS 20B?

Claude 4 Sonnet leads in math with an average score of 72 vs 30.

Which is better for reasoning, Claude 4 Sonnet or GPT-OSS 20B?

Claude 4 Sonnet leads in reasoning with an average score of 70 vs 28.

Related Comparisons

Claude 4 Sonnet vs GPT-5.4Claude 4 Sonnet vs Gemini 3.1 ProClaude 4 Sonnet vs Claude Opus 4.6Claude 4 Sonnet vs GPT-5.3 CodexClaude 4 Sonnet vs Grok 4.1Claude 4 Sonnet vs GPT-5.2