Gemini 2.5 Flash Preview (thinking) vs xAI: Grok 4 Fast (free)
Compare Gemini 2.5 Flash Preview (thinking) by Google AI against xAI: Grok 4 Fast (free) by xAI, context windows of 1.0M vs 2.0M, tested across 20 shared challenges.
Our Verdict
xAI: Grok 4 Fast (free)
Gemini 2.5 Flash Preview (thinking)Runner-up
No community votes yet. On paper, xAI: Grok 4 Fast (free) has the edge — bigger model tier, newer, bigger context window.
Slight edge
API pricing
Cost per 1M tokens
Gemini 2.5 Flash Preview (thinking)
Input
$0.17
Output
$3.50
xAI: Grok 4 Fast (free)
Input
$0.000
Output
$0.000
Writing DNA
Style Comparison
Similarity
64%
xAI: Grok 4 Fast (free) uses 157.7x more headings
Gemini 2.5 Flash Preview (thinking)
xAI: Grok 4 Fast (free)
53%Vocabulary65%
14wSentence Length13w
0.38Hedging0.56
4.4Bold1.4
4.1Lists2.5
0.00Emoji0.00
0.00Headings1.58
0.24Transitions0.28
Based on 7 + 14 text responses
Research
What we learned reading every model
FAQ
