OpenAI: GPT-5.6 Luna vs xAI: Grok 4.3
Compare OpenAI: GPT-5.6 Luna by OpenAI against xAI: Grok 4.3 by xAI, context windows of 1.1M vs 1.0M, tested across 54 shared challenges.
Our Verdict
OpenAI: GPT-5.6 Luna
xAI: Grok 4.3
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
OpenAI: GPT-5.6 Luna
Input
$1.00
1.3× cheaper
Output
$6.00
xAI: Grok 4.3
Input
$1.25
Output
$2.50
2.4× cheaper
OpenAI: GPT-5.6 Luna wins input (1.3× cheaper)·xAI: Grok 4.3 wins output (2.4× cheaper)
Writing DNA
Style Comparison
Similarity
68%
OpenAI: GPT-5.6 Luna uses 3.5x more headings
OpenAI: GPT-5.6 Luna
xAI: Grok 4.3
59%Vocabulary62%
19wSentence Length16w
0.84Hedging0.46
2.7Bold2.3
4.5Lists2.5
0.00Emoji0.00
1.20Headings0.34
0.10Transitions0.14
Based on 27 + 27 text responses
Research
What we learned reading every model
FAQ
