benchlm.ai

GPT-OSS 120B 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 42 (29 point difference).Kimi K2.5 (Reasoning) wins 4 out of 4 categories.

GPT-OSS 120B

CreatorOpenAI
TypeOpen Weight
Context128K
Score42

Kimi K2.5 (Reasoning)

CreatorMoonshot AI
TypeOpen Weight
Context128K
Score71

Knowledge

Kimi K2.5 (Reasoning)

GPT-OSS 120B

48.8

Kimi K2.5 (Reasoning)

89

51
MMLU
92
50
GPQA
90
48
SuperGPQA
88
46
OpenBookQA
86

Coding

Kimi K2.5 (Reasoning)

GPT-OSS 120B

43

Kimi K2.5 (Reasoning)

84

43
HumanEval
84

Mathematics

Kimi K2.5 (Reasoning)

GPT-OSS 120B

50

Kimi K2.5 (Reasoning)

93

51
AIME 2023
94
53
AIME 2024
96
52
AIME 2025
95
47
HMMT Feb 2023
90
49
HMMT Feb 2024
92
48
HMMT Feb 2025
91
50
BRUMO 2025
93

Reasoning

Kimi K2.5 (Reasoning)

GPT-OSS 120B

48

Kimi K2.5 (Reasoning)

87

49
SimpleQA
88
47
MuSR
86

Frequently Asked Questions

Which is better, GPT-OSS 120B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) scores higher overall with 71 vs 42, a difference of 29 points across all benchmarks.

Which is better for knowledge tasks, GPT-OSS 120B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in knowledge tasks with an average score of 89 vs 48.8.

Which is better for coding, GPT-OSS 120B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in coding with an average score of 84 vs 43.

Which is better for math, GPT-OSS 120B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in math with an average score of 93 vs 50.

Which is better for reasoning, GPT-OSS 120B or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) leads in reasoning with an average score of 87 vs 48.

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