GPT-5.2-Codex 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 82 (3 point difference).GPT-5.3 Codex wins 0 out of 4 categories.

Knowledge

Tie

GPT-5.2-Codex

96

GPT-5.3 Codex

96

99
MMLU
99
97
GPQA
97
95
SuperGPQA
95
93
OpenBookQA
93

Coding

Tie

GPT-5.2-Codex

95

GPT-5.3 Codex

95

95
HumanEval
95

Mathematics

Tie

GPT-5.2-Codex

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

Tie

GPT-5.2-Codex

94

GPT-5.3 Codex

94

95
SimpleQA
95
93
MuSR
93

Frequently Asked Questions

Which is better, GPT-5.2-Codex or GPT-5.3 Codex?

GPT-5.3 Codex scores higher overall with 85 vs 82, a difference of 3 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.2-Codex or GPT-5.3 Codex?

GPT-5.2-Codex and GPT-5.3 Codex are tied for knowledge tasks with average scores of 96.

Which is better for coding, GPT-5.2-Codex or GPT-5.3 Codex?

GPT-5.2-Codex and GPT-5.3 Codex are tied for coding with average scores of 95.

Which is better for math, GPT-5.2-Codex or GPT-5.3 Codex?

GPT-5.2-Codex and GPT-5.3 Codex are tied for math with average scores of 97.1.

Which is better for reasoning, GPT-5.2-Codex or GPT-5.3 Codex?

GPT-5.2-Codex and GPT-5.3 Codex are tied for reasoning with average scores of 94.