GPT-5 Pro vs Grok 3
Compare GPT-5 Pro by OpenAI against Grok 3 by xAI, context windows of 400K vs 128K, tested across 42 shared challenges. Updated May 2026.
Which is better, GPT-5 Pro or Grok 3?
GPT-5 Pro and Grok 3 are both competitive models. Context windows: 400K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between GPT-5 Pro and Grok 3
GPT-5 Pro is made by openai while Grok 3 is from xai. GPT-5 Pro has a 400K token context window compared to Grok 3's 128K.
API pricing
Per 1M tokens
GPT-5 Pro
Input
$15.00
Output
$120.00
Grok 3
Input
—
Output
—
Our Verdict
GPT-5 Pro
Grok 3Runner-up
No community votes yet. On paper, GPT-5 Pro has the edge — newer, bigger context window.
Too close to call
Writing DNA
Style Comparison
Similarity
55%
Grok 3 uses 246.4x more bold
GPT-5 Pro
Grok 3
65%Vocabulary49%
15wSentence Length18w
0.32Hedging0.94
0.0Bold2.5
2.9Lists3.0
0.00Emoji0.04
0.00Headings0.65
0.01Transitions0.08
Based on 11 + 17 text responses
FAQ
