benchlm.ai

GPT-5.1-Codex-Max vs Grok Code Fast 1

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 54 (23 point difference).GPT-5.1-Codex-Max wins 4 out of 4 categories.

GPT-5.1-Codex-Max

CreatorOpenAI
TypeProprietary
Context400K
Score77

Grok Code Fast 1

CreatorxAI
TypeProprietary
Context256K
Score54

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

95

Grok Code Fast 1

61.8

98
MMLU
64
96
GPQA
63
94
SuperGPQA
61
92
OpenBookQA
59

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94

Grok Code Fast 1

60

94
HumanEval
60

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

97.1

Grok Code Fast 1

63

99
AIME 2023
64
99
AIME 2024
66
98
AIME 2025
65
95
HMMT Feb 2023
60
97
HMMT Feb 2024
62
96
HMMT Feb 2025
61
96
BRUMO 2025
63

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

93

Grok Code Fast 1

60

94
SimpleQA
61
92
MuSR
59

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or Grok Code Fast 1?

GPT-5.1-Codex-Max scores higher overall with 77 vs 54, a difference of 23 points across all benchmarks.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or Grok Code Fast 1?

GPT-5.1-Codex-Max leads in knowledge tasks with an average score of 95 vs 61.8.

Which is better for coding, GPT-5.1-Codex-Max or Grok Code Fast 1?

GPT-5.1-Codex-Max leads in coding with an average score of 94 vs 60.

Which is better for math, GPT-5.1-Codex-Max or Grok Code Fast 1?

GPT-5.1-Codex-Max leads in math with an average score of 97.1 vs 63.

Which is better for reasoning, GPT-5.1-Codex-Max or Grok Code Fast 1?

GPT-5.1-Codex-Max leads in reasoning with an average score of 93 vs 60.

Related Comparisons

GPT-5.1-Codex-Max vs GPT-5.4GPT-5.1-Codex-Max vs Gemini 3.1 ProGPT-5.1-Codex-Max vs Claude Opus 4.6GPT-5.1-Codex-Max vs GPT-5.3 CodexGPT-5.1-Codex-Max vs Grok 4.1GPT-5.1-Codex-Max vs GPT-5.2