benchlm.ai

GPT-4o vs GPT-5.1-Codex-Max

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 56 (21 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-4o

CreatorOpenAI
TypeProprietary
Context128K
Score56

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Knowledge

GPT-5.1-Codex-Max

GPT-4o

64.5

GPT-5.1-Codex-Max

95

66
MMLU
98
66
GPQA
96
64
SuperGPQA
94
62
OpenBookQA
92

Coding

GPT-5.1-Codex-Max

GPT-4o

58

GPT-5.1-Codex-Max

94

58
HumanEval
94

Mathematics

GPT-5.1-Codex-Max

GPT-4o

65

GPT-5.1-Codex-Max

97.1

66
AIME 2023
99
68
AIME 2024
99
67
AIME 2025
98
62
HMMT Feb 2023
95
64
HMMT Feb 2024
97
63
HMMT Feb 2025
96
65
BRUMO 2025
96

Reasoning

GPT-5.1-Codex-Max

GPT-4o

63

GPT-5.1-Codex-Max

93

64
SimpleQA
94
62
MuSR
92

Frequently Asked Questions

Which is better, GPT-4o or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max scores higher overall with 77 vs 56, a difference of 21 points across all benchmarks.

Which is better for knowledge tasks, GPT-4o or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 64.5.

Which is better for coding, GPT-4o or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 58.

Which is better for math, GPT-4o or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 65.

Which is better for reasoning, GPT-4o or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 63.

Related Comparisons

GPT-4o vs GPT-5.4GPT-4o vs Gemini 3.1 ProGPT-4o vs Claude Opus 4.6GPT-4o vs GPT-5.3 CodexGPT-4o vs Grok 4.1GPT-4o vs GPT-5.2