benchlm.ai

Claude 3 Opus vs GPT-5.2-Codex

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

Quick Verdict

GPT-5.2-Codex wins overall with a score of 82 vs 51 (31 point difference).GPT-5.2-Codex wins 4 out of 4 categories.

Claude 3 Opus

CreatorAnthropic
TypeProprietary
Context200K
Score51

GPT-5.2-Codex

CreatorOpenAI
TypeProprietary
Context400K
Score82

Knowledge

GPT-5.2-Codex

Claude 3 Opus

59.5

GPT-5.2-Codex

96

61
MMLU
99
61
GPQA
97
59
SuperGPQA
95
57
OpenBookQA
93

Coding

GPT-5.2-Codex

Claude 3 Opus

53

GPT-5.2-Codex

95

53
HumanEval
95

Mathematics

GPT-5.2-Codex

Claude 3 Opus

60

GPT-5.2-Codex

97.1

61
AIME 2023
99
63
AIME 2024
99
62
AIME 2025
98
57
HMMT Feb 2023
95
59
HMMT Feb 2024
97
58
HMMT Feb 2025
96
60
BRUMO 2025
96

Reasoning

GPT-5.2-Codex

Claude 3 Opus

58

GPT-5.2-Codex

94

59
SimpleQA
95
57
MuSR
93

Frequently Asked Questions

Which is better, Claude 3 Opus or GPT-5.2-Codex?

GPT-5.2-Codex scores higher overall with 82 vs 51, a difference of 31 points across all benchmarks.

Which is better for knowledge tasks, Claude 3 Opus or GPT-5.2-Codex?

GPT-5.2-Codex leads in knowledge tasks with an average score of 96 vs 59.5.

Which is better for coding, Claude 3 Opus or GPT-5.2-Codex?

GPT-5.2-Codex leads in coding with an average score of 95 vs 53.

Which is better for math, Claude 3 Opus or GPT-5.2-Codex?

GPT-5.2-Codex leads in math with an average score of 97.1 vs 60.

Which is better for reasoning, Claude 3 Opus or GPT-5.2-Codex?

GPT-5.2-Codex leads in reasoning with an average score of 94 vs 58.

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