benchlm.ai

Claude 3.5 Sonnet vs GPT-OSS 20B

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

Quick Verdict

Claude 3.5 Sonnet wins overall with a score of 55 vs 22 (33 point difference).Claude 3.5 Sonnet wins 4 out of 4 categories.

Claude 3.5 Sonnet

CreatorAnthropic
TypeProprietary
Context200K
Score55

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Knowledge

Claude 3.5 Sonnet

Claude 3.5 Sonnet

63.5

GPT-OSS 20B

28.8

65
MMLU
31
65
GPQA
30
63
SuperGPQA
28
61
OpenBookQA
26

Coding

Claude 3.5 Sonnet

Claude 3.5 Sonnet

57

GPT-OSS 20B

23

57
HumanEval
23

Mathematics

Claude 3.5 Sonnet

Claude 3.5 Sonnet

64

GPT-OSS 20B

30

65
AIME 2023
31
67
AIME 2024
33
66
AIME 2025
32
61
HMMT Feb 2023
27
63
HMMT Feb 2024
29
62
HMMT Feb 2025
28
64
BRUMO 2025
30

Reasoning

Claude 3.5 Sonnet

Claude 3.5 Sonnet

62

GPT-OSS 20B

28

63
SimpleQA
29
61
MuSR
27

Frequently Asked Questions

Which is better, Claude 3.5 Sonnet or GPT-OSS 20B?

Claude 3.5 Sonnet scores higher overall with 55 vs 22, a difference of 33 points across all benchmarks.

Which is better for knowledge tasks, Claude 3.5 Sonnet or GPT-OSS 20B?

Claude 3.5 Sonnet leads in knowledge tasks with an average score of 63.5 vs 28.8.

Which is better for coding, Claude 3.5 Sonnet or GPT-OSS 20B?

Claude 3.5 Sonnet leads in coding with an average score of 57 vs 23.

Which is better for math, Claude 3.5 Sonnet or GPT-OSS 20B?

Claude 3.5 Sonnet leads in math with an average score of 64 vs 30.

Which is better for reasoning, Claude 3.5 Sonnet or GPT-OSS 20B?

Claude 3.5 Sonnet leads in reasoning with an average score of 62 vs 28.

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