GPT-5.1 Chat vs GPT-5.6 Luna
Compare GPT-5.1 Chat and GPT-5.6 Luna, both from OpenAI, context windows of 128K vs 1.1M, tested across 52 shared challenges.
Our Verdict
GPT-5.1 Chat
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
GPT-5.1 Chat
Input
$1.25
Output
$10.00
GPT-5.6 Luna
Input
$1.00
1.3× cheaper
Output
$6.00
1.7× cheaper
GPT-5.6 Luna is cheaper on both — 1.3× input, 1.7× output
Writing DNA
Style Comparison
Similarity
51%
GPT-5.6 Luna uses 119.5x more headings
GPT-5.1 Chat
GPT-5.6 Luna
73%Vocabulary59%
18wSentence Length19w
0.45Hedging0.84
1.1Bold2.7
2.4Lists4.5
0.00Emoji0.00
0.00Headings1.20
0.06Transitions0.10
Based on 15 + 27 text responses
Research
What we learned reading every model
FAQ
Common questions
Keep exploring
