benchlm.ai

GPT-5.3 Codex vs Qwen3.5 397B

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 65 (20 point difference).GPT-5.3 Codex wins 4 out of 4 categories.

GPT-5.3 Codex

CreatorOpenAI
TypeProprietary
Context400K
Score85

Qwen3.5 397B

CreatorAlibaba
TypeOpen Weight
Context128K
Score65

Knowledge

GPT-5.3 Codex

GPT-5.3 Codex

96

Qwen3.5 397B

80.8

99
MMLU
83
97
GPQA
82
95
SuperGPQA
80
93
OpenBookQA
78

Coding

GPT-5.3 Codex

GPT-5.3 Codex

95

Qwen3.5 397B

75

95
HumanEval
75

Mathematics

GPT-5.3 Codex

GPT-5.3 Codex

97.1

Qwen3.5 397B

82

99
AIME 2023
83
99
AIME 2024
85
98
AIME 2025
84
95
HMMT Feb 2023
79
97
HMMT Feb 2024
81
96
HMMT Feb 2025
80
96
BRUMO 2025
82

Reasoning

GPT-5.3 Codex

GPT-5.3 Codex

94

Qwen3.5 397B

79

95
SimpleQA
80
93
MuSR
78

Frequently Asked Questions

Which is better, GPT-5.3 Codex or Qwen3.5 397B?

GPT-5.3 Codex scores higher overall with 85 vs 65, a difference of 20 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.3 Codex or Qwen3.5 397B?

GPT-5.3 Codex leads in knowledge tasks with an average score of 96 vs 80.8.

Which is better for coding, GPT-5.3 Codex or Qwen3.5 397B?

GPT-5.3 Codex leads in coding with an average score of 95 vs 75.

Which is better for math, GPT-5.3 Codex or Qwen3.5 397B?

GPT-5.3 Codex leads in math with an average score of 97.1 vs 82.

Which is better for reasoning, GPT-5.3 Codex or Qwen3.5 397B?

GPT-5.3 Codex leads in reasoning with an average score of 94 vs 79.

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