GPT-5 mini vs o3

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

Quick Verdict

GPT-5 mini wins overall with a score of 68 vs 67 (1 point difference).GPT-5 mini wins 2 out of 4 categories.

Knowledge

o3

GPT-5 mini

85

o3

85.3

88
MMLU
86
86
GPQA
87
84
SuperGPQA
85
82
OpenBookQA
83

Coding

GPT-5 mini

GPT-5 mini

80

o3

78

80
HumanEval
78

Mathematics

GPT-5 mini

GPT-5 mini

89

o3

87

90
AIME 2023
88
92
AIME 2024
90
91
AIME 2025
89
86
HMMT Feb 2023
84
88
HMMT Feb 2024
86
87
HMMT Feb 2025
85
89
BRUMO 2025
87

Reasoning

Tie

GPT-5 mini

83

o3

83

84
SimpleQA
84
82
MuSR
82

Frequently Asked Questions

Which is better, GPT-5 mini or o3?

GPT-5 mini scores higher overall with 68 vs 67, a difference of 1 points across all benchmarks.

Which is better for knowledge tasks, GPT-5 mini or o3?

o3 leads in knowledge tasks with an average score of 85.3 vs 85.

Which is better for coding, GPT-5 mini or o3?

GPT-5 mini leads in coding with an average score of 80 vs 78.

Which is better for math, GPT-5 mini or o3?

GPT-5 mini leads in math with an average score of 89 vs 87.

Which is better for reasoning, GPT-5 mini or o3?

GPT-5 mini and o3 are tied for reasoning with average scores of 83.