GPT-5 (high) vs o3

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

Quick Verdict

GPT-5 (high) wins overall with a score of 72 vs 67 (5 point difference).GPT-5 (high) wins 4 out of 4 categories.

Knowledge

GPT-5 (high)

GPT-5 (high)

90

o3

85.3

93
MMLU
86
91
GPQA
87
89
SuperGPQA
85
87
OpenBookQA
83

Coding

GPT-5 (high)

GPT-5 (high)

85

o3

78

85
HumanEval
78

Mathematics

GPT-5 (high)

GPT-5 (high)

94

o3

87

95
AIME 2023
88
97
AIME 2024
90
96
AIME 2025
89
91
HMMT Feb 2023
84
93
HMMT Feb 2024
86
92
HMMT Feb 2025
85
94
BRUMO 2025
87

Reasoning

GPT-5 (high)

GPT-5 (high)

88

o3

83

89
SimpleQA
84
87
MuSR
82

Frequently Asked Questions

Which is better, GPT-5 (high) or o3?

GPT-5 (high) scores higher overall with 72 vs 67, a difference of 5 points across all benchmarks.

Which is better for knowledge tasks, GPT-5 (high) or o3?

GPT-5 (high) leads in knowledge tasks with an average score of 90 vs 85.3.

Which is better for coding, GPT-5 (high) or o3?

GPT-5 (high) leads in coding with an average score of 85 vs 78.

Which is better for math, GPT-5 (high) or o3?

GPT-5 (high) leads in math with an average score of 94 vs 87.

Which is better for reasoning, GPT-5 (high) or o3?

GPT-5 (high) leads in reasoning with an average score of 88 vs 83.