benchlm.ai

Gemini 3 Flash vs GPT-OSS 20B

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

Quick Verdict

Gemini 3 Flash wins overall with a score of 58 vs 22 (36 point difference).Gemini 3 Flash wins 4 out of 4 categories.

Gemini 3 Flash

CreatorGoogle
TypeProprietary
Context1M
Score58

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Knowledge

Gemini 3 Flash

Gemini 3 Flash

67.8

GPT-OSS 20B

28.8

70
MMLU
31
69
GPQA
30
67
SuperGPQA
28
65
OpenBookQA
26

Coding

Gemini 3 Flash

Gemini 3 Flash

62

GPT-OSS 20B

23

62
HumanEval
23

Mathematics

Gemini 3 Flash

Gemini 3 Flash

69

GPT-OSS 20B

30

70
AIME 2023
31
72
AIME 2024
33
71
AIME 2025
32
66
HMMT Feb 2023
27
68
HMMT Feb 2024
29
67
HMMT Feb 2025
28
69
BRUMO 2025
30

Reasoning

Gemini 3 Flash

Gemini 3 Flash

66

GPT-OSS 20B

28

67
SimpleQA
29
65
MuSR
27

Frequently Asked Questions

Which is better, Gemini 3 Flash or GPT-OSS 20B?

Gemini 3 Flash scores higher overall with 58 vs 22, a difference of 36 points across all benchmarks.

Which is better for knowledge tasks, Gemini 3 Flash or GPT-OSS 20B?

Gemini 3 Flash leads in knowledge tasks with an average score of 67.8 vs 28.8.

Which is better for coding, Gemini 3 Flash or GPT-OSS 20B?

Gemini 3 Flash leads in coding with an average score of 62 vs 23.

Which is better for math, Gemini 3 Flash or GPT-OSS 20B?

Gemini 3 Flash leads in math with an average score of 69 vs 30.

Which is better for reasoning, Gemini 3 Flash or GPT-OSS 20B?

Gemini 3 Flash leads in reasoning with an average score of 66 vs 28.

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