benchlm.ai

GPT-OSS 20B vs Kimi K2.5

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

Quick Verdict

Kimi K2.5 wins overall with a score of 62 vs 22 (40 point difference).Kimi K2.5 wins 4 out of 4 categories.

GPT-OSS 20B

CreatorOpenAI
TypeOpen Weight
Context128K
Score22

Kimi K2.5

CreatorMoonshot AI
TypeOpen Weight
Context128K
Score62

Knowledge

Kimi K2.5

GPT-OSS 20B

28.8

Kimi K2.5

74.8

31
MMLU
77
30
GPQA
76
28
SuperGPQA
74
26
OpenBookQA
72

Coding

Kimi K2.5

GPT-OSS 20B

23

Kimi K2.5

69

23
HumanEval
69

Mathematics

Kimi K2.5

GPT-OSS 20B

30

Kimi K2.5

76

31
AIME 2023
77
33
AIME 2024
79
32
AIME 2025
78
27
HMMT Feb 2023
73
29
HMMT Feb 2024
75
28
HMMT Feb 2025
74
30
BRUMO 2025
76

Reasoning

Kimi K2.5

GPT-OSS 20B

28

Kimi K2.5

73

29
SimpleQA
74
27
MuSR
72

Frequently Asked Questions

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

Kimi K2.5 scores higher overall with 62 vs 22, a difference of 40 points across all benchmarks.

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

Kimi K2.5 leads in knowledge tasks with an average score of 74.8 vs 28.8.

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

Kimi K2.5 leads in coding with an average score of 69 vs 23.

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

Kimi K2.5 leads in math with an average score of 76 vs 30.

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

Kimi K2.5 leads in reasoning with an average score of 73 vs 28.

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