benchlm.ai

Claude Sonnet 4.5 vs o3

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

Quick Verdict

Claude Sonnet 4.5 wins overall with a score of 74 vs 67 (7 point difference).Claude Sonnet 4.5 wins 4 out of 4 categories.

Claude Sonnet 4.5

CreatorAnthropic
TypeProprietary
Context1M
Score74

o3

CreatorOpenAI
TypeProprietary
Context200K
Score67

Knowledge

Claude Sonnet 4.5

Claude Sonnet 4.5

92

o3

85.3

95
MMLU
86
93
GPQA
87
91
SuperGPQA
85
89
OpenBookQA
83

Coding

Claude Sonnet 4.5

Claude Sonnet 4.5

87

o3

78

87
HumanEval
78

Mathematics

Claude Sonnet 4.5

Claude Sonnet 4.5

96

o3

87

97
AIME 2023
88
99
AIME 2024
90
98
AIME 2025
89
93
HMMT Feb 2023
84
95
HMMT Feb 2024
86
94
HMMT Feb 2025
85
96
BRUMO 2025
87

Reasoning

Claude Sonnet 4.5

Claude Sonnet 4.5

90

o3

83

91
SimpleQA
84
89
MuSR
82

Frequently Asked Questions

Which is better, Claude Sonnet 4.5 or o3?

Claude Sonnet 4.5 scores higher overall with 74 vs 67, a difference of 7 points across all benchmarks.

Which is better for knowledge tasks, Claude Sonnet 4.5 or o3?

Claude Sonnet 4.5 leads in knowledge tasks with an average score of 92 vs 85.3.

Which is better for coding, Claude Sonnet 4.5 or o3?

Claude Sonnet 4.5 leads in coding with an average score of 87 vs 78.

Which is better for math, Claude Sonnet 4.5 or o3?

Claude Sonnet 4.5 leads in math with an average score of 96 vs 87.

Which is better for reasoning, Claude Sonnet 4.5 or o3?

Claude Sonnet 4.5 leads in reasoning with an average score of 90 vs 83.

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