GPT-5.3 Chat vs xAI: Grok 4.5
Compare GPT-5.3 Chat by OpenAI against xAI: Grok 4.5 by xAI, context windows of 128K vs 500K, tested across 53 shared challenges.
Our Verdict
xAI: Grok 4.5
GPT-5.3 ChatRunner-up
No community votes yet. On paper, xAI: Grok 4.5 has the edge — newer, bigger context window.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.3 Chat
Input
$1.75
1.1× cheaper
Output
$14.00
xAI: Grok 4.5
Input
$2.00
Output
$6.00
2.3× cheaper
GPT-5.3 Chat wins input (1.1× cheaper)·xAI: Grok 4.5 wins output (2.3× cheaper)
Writing DNA
Style Comparison
Similarity
40%
xAI: Grok 4.5 uses 9.0x more emoji
GPT-5.3 Chat
xAI: Grok 4.5
59%Vocabulary61%
26wSentence Length16w
0.84Hedging0.23
1.7Bold2.5
6.6Lists2.4
0.00Emoji0.09
0.00Headings0.48
0.25Transitions0.06
Based on 23 + 27 text responses
Research
What we learned reading every model
FAQ
