benchlm.ai

GPT-5.1-Codex-Max vs Grok 4.1 Fast

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 73 (4 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Grok 4.1 Fast

CreatorxAI
TypeProprietary
Context2M
Score73

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

95

Grok 4.1 Fast

91

98
MMLU
94
96
GPQA
92
94
SuperGPQA
90
92
OpenBookQA
88

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94

Grok 4.1 Fast

86

94
HumanEval
86

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

97.1

Grok 4.1 Fast

95

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

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

93

Grok 4.1 Fast

89

94
SimpleQA
90
92
MuSR
88

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or Grok 4.1 Fast?

GPT-5.1-Codex-Max scores higher overall with 77 vs 73, a difference of 4 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or Grok 4.1 Fast?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 91.

Which is better for coding, GPT-5.1-Codex-Max or Grok 4.1 Fast?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 86.

Which is better for math, GPT-5.1-Codex-Max or Grok 4.1 Fast?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 95.

Which is better for reasoning, GPT-5.1-Codex-Max or Grok 4.1 Fast?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 89.

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