benchlm.ai

Claude Haiku 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 57 (20 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

Claude Haiku 4.5

CreatorAnthropic
TypeProprietary
Context200K
Score57

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Knowledge

GPT-5.1-Codex-Max

Claude Haiku 4.5

65.8

GPT-5.1-Codex-Max

95

68
MMLU
98
67
GPQA
96
65
SuperGPQA
94
63
OpenBookQA
92

Coding

GPT-5.1-Codex-Max

Claude Haiku 4.5

60

GPT-5.1-Codex-Max

94

60
HumanEval
94

Mathematics

GPT-5.1-Codex-Max

Claude Haiku 4.5

67

GPT-5.1-Codex-Max

97.1

68
AIME 2023
99
70
AIME 2024
99
69
AIME 2025
98
64
HMMT Feb 2023
95
66
HMMT Feb 2024
97
65
HMMT Feb 2025
96
67
BRUMO 2025
96

Reasoning

GPT-5.1-Codex-Max

Claude Haiku 4.5

64

GPT-5.1-Codex-Max

93

65
SimpleQA
94
63
MuSR
92

Frequently Asked Questions

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

GPT-5.1-Codex-Max scores higher overall with 77 vs 57, a difference of 20 points across all benchmarks.

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

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 65.8.

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

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 60.

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

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 67.

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

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 64.

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