Side-by-side benchmark comparison across knowledge, coding, math, and reasoning.
GPT-5.3 Codex wins overall with a score of 85 vs 67 (18 point difference).GPT-5.3 Codex wins 4 out of 4 categories.
GPT-5.3 Codex
96
o3
85.3
GPT-5.3 Codex
95
o3
78
GPT-5.3 Codex
97.1
o3
87
GPT-5.3 Codex
94
o3
83
GPT-5.3 Codex scores higher overall with 85 vs 67, a difference of 18 points across all benchmarks.
GPT-5.3 Codex leads in knowledge tasks with an average score of 96 vs 85.3.
GPT-5.3 Codex leads in coding with an average score of 95 vs 78.
GPT-5.3 Codex leads in math with an average score of 97.1 vs 87.
GPT-5.3 Codex leads in reasoning with an average score of 94 vs 83.