GPT-4.5 vs xAI: Grok 4 Fast (free)
Compare GPT-4.5 by OpenAI against xAI: Grok 4 Fast (free) by xAI, context windows of 128K vs 2.0M, tested across 22 shared challenges.
Our Verdict
GPT-4.5
xAI: Grok 4 Fast (free)
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Too close to call
API pricing
Cost per 1M tokens
GPT-4.5
Input
$75.00
Output
$150.00
xAI: Grok 4 Fast (free)
Input
$0.000
Output
$0.000
Writing DNA
Style Comparison
Similarity
63%
GPT-4.5 uses 3.4x more bold
GPT-4.5
xAI: Grok 4 Fast (free)
63%Vocabulary65%
16wSentence Length13w
0.57Hedging0.56
4.7Bold1.4
6.4Lists2.5
0.00Emoji0.00
1.30Headings1.58
0.54Transitions0.28
Based on 11 + 14 text responses
Research
What we learned reading every model
FAQ
