benchlm.ai

GPT-5.1-Codex-Max vs o3-pro

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 68 (9 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

o3-pro

CreatorOpenAI
TypeProprietary
Context200K
Score68

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

95

o3-pro

87.3

98
MMLU
88
96
GPQA
89
94
SuperGPQA
87
92
OpenBookQA
85

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94

o3-pro

80

94
HumanEval
80

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

97.1

o3-pro

89

99
AIME 2023
90
99
AIME 2024
92
98
AIME 2025
91
95
HMMT Feb 2023
86
97
HMMT Feb 2024
88
96
HMMT Feb 2025
87
96
BRUMO 2025
89

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

93

o3-pro

85

94
SimpleQA
86
92
MuSR
84

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or o3-pro?

GPT-5.1-Codex-Max scores higher overall with 77 vs 68, a difference of 9 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or o3-pro?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 87.3.

Which is better for coding, GPT-5.1-Codex-Max or o3-pro?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 80.

Which is better for math, GPT-5.1-Codex-Max or o3-pro?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 89.

Which is better for reasoning, GPT-5.1-Codex-Max or o3-pro?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 85.

Related Comparisons

GPT-5.1-Codex-Max vs GPT-5.4GPT-5.1-Codex-Max vs Gemini 3.1 ProGPT-5.1-Codex-Max vs Claude Opus 4.6GPT-5.1-Codex-Max vs GPT-5.3 CodexGPT-5.1-Codex-Max vs Grok 4.1GPT-5.1-Codex-Max vs GPT-5.2