GPT-5.5 vs Grok Code Fast 1
Compare GPT-5.5 by OpenAI against Grok Code Fast 1 by xAI, context windows of 1.1M vs 256K, tested across 54 shared challenges.
Our Verdict
GPT-5.5
Grok Code Fast 1Runner-up
No community votes yet. On paper, GPT-5.5 has the edge — bigger model tier, newer, bigger context window.
Grok Code Fast 1 is 20x cheaper per token — worth considering if cost matters.
Slight edge
API pricing
Cost per 1M tokens
GPT-5.5
Input
$5.00
Output
$30.00
Grok Code Fast 1
Input
$0.20
25× cheaper
Output
$1.50
20× cheaper
Grok Code Fast 1 is cheaper on both — 25× input, 20× output
Writing DNA
Style Comparison
Similarity
56%
Grok Code Fast 1 uses 6.0x more emoji
GPT-5.5
Grok Code Fast 1
58%Vocabulary60%
18wSentence Length17w
0.74Hedging0.97
2.9Bold2.8
5.1Lists2.5
0.00Emoji0.06
1.68Headings0.89
0.03Transitions0.11
Based on 26 + 23 text responses
Research
What we learned reading every model
FAQ
