benchlm.ai

GPT-5.1-Codex-Max vs Qwen3.5 397B (Reasoning)

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 70 (7 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Qwen3.5 397B (Reasoning)

CreatorAlibaba
TypeOpen Weight
Context128K
Score70

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

95

Qwen3.5 397B (Reasoning)

88

98
MMLU
91
96
GPQA
89
94
SuperGPQA
87
92
OpenBookQA
85

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94

Qwen3.5 397B (Reasoning)

83

94
HumanEval
83

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

97.1

Qwen3.5 397B (Reasoning)

92

99
AIME 2023
93
99
AIME 2024
95
98
AIME 2025
94
95
HMMT Feb 2023
89
97
HMMT Feb 2024
91
96
HMMT Feb 2025
90
96
BRUMO 2025
92

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

93

Qwen3.5 397B (Reasoning)

86

94
SimpleQA
87
92
MuSR
85

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or Qwen3.5 397B (Reasoning)?

GPT-5.1-Codex-Max scores higher overall with 77 vs 70, a difference of 7 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or Qwen3.5 397B (Reasoning)?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 88.

Which is better for coding, GPT-5.1-Codex-Max or Qwen3.5 397B (Reasoning)?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 83.

Which is better for math, GPT-5.1-Codex-Max or Qwen3.5 397B (Reasoning)?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 92.

Which is better for reasoning, GPT-5.1-Codex-Max or Qwen3.5 397B (Reasoning)?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 86.

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