benchlm.ai

GPT-5.1-Codex-Max vs Kimi K2

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

Quick Verdict

GPT-5.1-Codex-Max wins overall with a score of 77 vs 23 (54 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Kimi K2

CreatorMoonshot AI
TypeProprietary
Context128K
Score23

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

95

Kimi K2

29.8

98
MMLU
32
96
GPQA
31
94
SuperGPQA
29
92
OpenBookQA
27

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94

Kimi K2

24

94
HumanEval
24

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

97.1

Kimi K2

31

99
AIME 2023
32
99
AIME 2024
34
98
AIME 2025
33
95
HMMT Feb 2023
28
97
HMMT Feb 2024
30
96
HMMT Feb 2025
29
96
BRUMO 2025
31

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

93

Kimi K2

29

94
SimpleQA
30
92
MuSR
28

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or Kimi K2?

GPT-5.1-Codex-Max scores higher overall with 77 vs 23, a difference of 54 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or Kimi K2?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 29.8.

Which is better for coding, GPT-5.1-Codex-Max or Kimi K2?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 24.

Which is better for math, GPT-5.1-Codex-Max or Kimi K2?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 31.

Which is better for reasoning, GPT-5.1-Codex-Max or Kimi K2?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 29.

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