benchlm.ai

Claude Sonnet 4.5 vs GPT-5.1-Codex-Max

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

Quick Verdict

GPT-5.1-Codex-Max wins overall with a score of 77 vs 74 (3 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

Claude Sonnet 4.5

CreatorAnthropic
TypeProprietary
Context1M
Score74

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Knowledge

GPT-5.1-Codex-Max

Claude Sonnet 4.5

92

GPT-5.1-Codex-Max

95

95
MMLU
98
93
GPQA
96
91
SuperGPQA
94
89
OpenBookQA
92

Coding

GPT-5.1-Codex-Max

Claude Sonnet 4.5

87

GPT-5.1-Codex-Max

94

87
HumanEval
94

Mathematics

GPT-5.1-Codex-Max

Claude Sonnet 4.5

96

GPT-5.1-Codex-Max

97.1

97
AIME 2023
99
99
AIME 2024
99
98
AIME 2025
98
93
HMMT Feb 2023
95
95
HMMT Feb 2024
97
94
HMMT Feb 2025
96
96
BRUMO 2025
96

Reasoning

GPT-5.1-Codex-Max

Claude Sonnet 4.5

90

GPT-5.1-Codex-Max

93

91
SimpleQA
94
89
MuSR
92

Frequently Asked Questions

Which is better, Claude Sonnet 4.5 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max scores higher overall with 77 vs 74, a difference of 3 points across all benchmarks.

Which is better for knowledge tasks, Claude Sonnet 4.5 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 92.

Which is better for coding, Claude Sonnet 4.5 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 87.

Which is better for math, Claude Sonnet 4.5 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 96.

Which is better for reasoning, Claude Sonnet 4.5 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 90.

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