benchlm.ai

Gemini 2.5 Flash vs GPT-OSS 20B

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

Quick Verdict

Gemini 2.5 Flash wins overall with a score of 41 vs 22 (19 point difference).Gemini 2.5 Flash wins 4 out of 4 categories.

Gemini 2.5 Flash

CreatorGoogle
TypeProprietary
Context1M
Score41

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Knowledge

Gemini 2.5 Flash

Gemini 2.5 Flash

47.8

GPT-OSS 20B

28.8

50
MMLU
31
49
GPQA
30
47
SuperGPQA
28
45
OpenBookQA
26

Coding

Gemini 2.5 Flash

Gemini 2.5 Flash

42

GPT-OSS 20B

23

42
HumanEval
23

Mathematics

Gemini 2.5 Flash

Gemini 2.5 Flash

49

GPT-OSS 20B

30

50
AIME 2023
31
52
AIME 2024
33
51
AIME 2025
32
46
HMMT Feb 2023
27
48
HMMT Feb 2024
29
47
HMMT Feb 2025
28
49
BRUMO 2025
30

Reasoning

Gemini 2.5 Flash

Gemini 2.5 Flash

47

GPT-OSS 20B

28

48
SimpleQA
29
46
MuSR
27

Frequently Asked Questions

Which is better, Gemini 2.5 Flash or GPT-OSS 20B?

Gemini 2.5 Flash scores higher overall with 41 vs 22, a difference of 19 points across all benchmarks.

Which is better for knowledge tasks, Gemini 2.5 Flash or GPT-OSS 20B?

Gemini 2.5 Flash leads in knowledge tasks with an average score of 47.8 vs 28.8.

Which is better for coding, Gemini 2.5 Flash or GPT-OSS 20B?

Gemini 2.5 Flash leads in coding with an average score of 42 vs 23.

Which is better for math, Gemini 2.5 Flash or GPT-OSS 20B?

Gemini 2.5 Flash leads in math with an average score of 49 vs 30.

Which is better for reasoning, Gemini 2.5 Flash or GPT-OSS 20B?

Gemini 2.5 Flash leads in reasoning with an average score of 47 vs 28.

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