benchlm.ai

GPT-OSS 20B vs Kimi K2.5 (Reasoning)

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

Quick Verdict

Kimi K2.5 (Reasoning) wins overall with a score of 71 vs 22 (49 point difference).Kimi K2.5 (Reasoning) wins 4 out of 4 categories.

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Kimi K2.5 (Reasoning)

CreatorMoonshot AI
TypeOpen Weight
Context128K
Score71

Knowledge

Kimi K2.5 (Reasoning)

GPT-OSS 20B

28.8

Kimi K2.5 (Reasoning)

89

31
MMLU
92
30
GPQA
90
28
SuperGPQA
88
26
OpenBookQA
86

Coding

Kimi K2.5 (Reasoning)

GPT-OSS 20B

23

Kimi K2.5 (Reasoning)

84

23
HumanEval
84

Mathematics

Kimi K2.5 (Reasoning)

GPT-OSS 20B

30

Kimi K2.5 (Reasoning)

93

31
AIME 2023
94
33
AIME 2024
96
32
AIME 2025
95
27
HMMT Feb 2023
90
29
HMMT Feb 2024
92
28
HMMT Feb 2025
91
30
BRUMO 2025
93

Reasoning

Kimi K2.5 (Reasoning)

GPT-OSS 20B

28

Kimi K2.5 (Reasoning)

87

29
SimpleQA
88
27
MuSR
86

Frequently Asked Questions

Which is better, GPT-OSS 20B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) scores higher overall with 71 vs 22, a difference of 49 points across all benchmarks.

Which is better for knowledge tasks, GPT-OSS 20B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in knowledge tasks with an average score of 89 vs 28.8.

Which is better for coding, GPT-OSS 20B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in coding with an average score of 84 vs 23.

Which is better for math, GPT-OSS 20B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in math with an average score of 93 vs 30.

Which is better for reasoning, GPT-OSS 20B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in reasoning with an average score of 87 vs 28.

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