benchlm.ai

GPT-5.1-Codex-Max vs GPT-5.3 Codex

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

Quick Verdict

GPT-5.3 Codex wins overall with a score of 85 vs 77 (8 point difference).GPT-5.3 Codex wins 3 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

GPT-5.3 Codex

CreatorOpenAI
TypeProprietary
Context400K
Score85

Knowledge

GPT-5.3 Codex

GPT-5.1-Codex-Max

95

GPT-5.3 Codex

96

98
MMLU
99
96
GPQA
97
94
SuperGPQA
95
92
OpenBookQA
93

Coding

GPT-5.3 Codex

GPT-5.1-Codex-Max

94

GPT-5.3 Codex

95

94
HumanEval
95

Mathematics

Tie

GPT-5.1-Codex-Max

97.1

GPT-5.3 Codex

97.1

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

Reasoning

GPT-5.3 Codex

GPT-5.1-Codex-Max

93

GPT-5.3 Codex

94

94
SimpleQA
95
92
MuSR
93

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or GPT-5.3 Codex?

GPT-5.3 Codex scores higher overall with 85 vs 77, a difference of 8 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or GPT-5.3 Codex?

GPT-5.3 Codex leads in knowledge tasks with an average score of 96 vs 95.

Which is better for coding, GPT-5.1-Codex-Max or GPT-5.3 Codex?

GPT-5.3 Codex leads in coding with an average score of 95 vs 94.

Which is better for math, GPT-5.1-Codex-Max or GPT-5.3 Codex?

GPT-5.1-Codex-Max and GPT-5.3 Codex are tied for math with average scores of 97.1.

Which is better for reasoning, GPT-5.1-Codex-Max or GPT-5.3 Codex?

GPT-5.3 Codex leads in reasoning with an average score of 94 vs 93.

Related Comparisons

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