GPT-5.1 vs Grok 3 Thinking

Compare GPT-5.1 by OpenAI against Grok 3 Thinking by xAI, context windows of 400K vs 128K, tested across 14 shared challenges. Updated April 2026.

Which is better, GPT-5.1 or Grok 3 Thinking?

GPT-5.1 and Grok 3 Thinking are both competitive models. Context windows: 400K vs 128K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-5.1 and Grok 3 Thinking

GPT-5.1 is made by openai while Grok 3 Thinking is from xai. GPT-5.1 has a 400K token context window compared to Grok 3 Thinking's 128K.

Our Verdict
GPT-5.1
GPT-5.1
Grok 3 Thinking
Grok 3 ThinkingRunner-up

No community votes yet. On paper, GPT-5.1 has the edge — newer, bigger context window.

Too close to call
Writing DNA

Style Comparison

Similarity
98%

Grok 3 Thinking uses 9.2x more transitions

GPT-5.1
Grok 3 Thinking
62%Vocabulary46%
19wSentence Length19w
0.29Hedging1.11
3.5Bold3.3
7.2Lists2.6
0.00Emoji0.00
0.61Headings0.64
0.03Transitions0.25
Based on 14 + 6 text responses
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GPT-5.1Grok 3 Thinking

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