ChatGPT-4o (March 2025) vs GPT-5.6 Luna
Compare ChatGPT-4o (March 2025) and GPT-5.6 Luna, both from OpenAI, context windows of 128K vs 1.1M, tested across 32 shared challenges.
Our Verdict
ChatGPT-4o (March 2025)
GPT-5.6 Luna
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
ChatGPT-4o (March 2025)
Input
$5.00
Output
$15.00
GPT-5.6 Luna
Input
$1.00
5.0× cheaper
Output
$6.00
2.5× cheaper
GPT-5.6 Luna is cheaper on both — 5.0× input, 2.5× output
Writing DNA
Style Comparison
Similarity
46%
ChatGPT-4o (March 2025) uses 94.5x more emoji
ChatGPT-4o (March 2025)
GPT-5.6 Luna
55%Vocabulary59%
24wSentence Length19w
0.52Hedging0.84
3.3Bold2.7
6.0Lists4.5
0.94Emoji0.00
0.63Headings1.20
0.05Transitions0.10
Based on 15 + 27 text responses
Research
What we learned reading every model
FAQ
