Llama 3.1 405B vs o3

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

Quick Verdict

o3 wins overall with a score of 67 vs 58 (9 point difference).o3 wins 4 out of 4 categories.

Knowledge

o3

Llama 3.1 405B

68.5

o3

85.3

70
MMLU
86
70
GPQA
87
68
SuperGPQA
85
66
OpenBookQA
83

Coding

o3

Llama 3.1 405B

62

o3

78

62
HumanEval
78

Mathematics

o3

Llama 3.1 405B

69

o3

87

70
AIME 2023
88
72
AIME 2024
90
71
AIME 2025
89
66
HMMT Feb 2023
84
68
HMMT Feb 2024
86
67
HMMT Feb 2025
85
69
BRUMO 2025
87

Reasoning

o3

Llama 3.1 405B

67

o3

83

68
SimpleQA
84
66
MuSR
82

Frequently Asked Questions

Which is better, Llama 3.1 405B or o3?

o3 scores higher overall with 67 vs 58, a difference of 9 points across all benchmarks.

Which is better for knowledge tasks, Llama 3.1 405B or o3?

o3 leads in knowledge tasks with an average score of 85.3 vs 68.5.

Which is better for coding, Llama 3.1 405B or o3?

o3 leads in coding with an average score of 78 vs 62.

Which is better for math, Llama 3.1 405B or o3?

o3 leads in math with an average score of 87 vs 69.

Which is better for reasoning, Llama 3.1 405B or o3?

o3 leads in reasoning with an average score of 83 vs 67.