Claude Sonnet 4 vs OpenAI: GPT-5.6 Luna
Compare Claude Sonnet 4 by Anthropic against OpenAI: GPT-5.6 Luna by OpenAI, context windows of 200K vs 1.1M, tested across 53 shared challenges.
Our Verdict
Claude Sonnet 4
OpenAI: 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
Claude Sonnet 4
Input
$3.00
Output
$15.00
OpenAI: GPT-5.6 Luna
Input
$1.00
3.0× cheaper
Output
$6.00
2.5× cheaper
OpenAI: GPT-5.6 Luna is cheaper on both — 3.0× input, 2.5× output
Writing DNA
Style Comparison
Similarity
50%
Claude Sonnet 4 uses 87.9x more emoji
Claude Sonnet 4
OpenAI: GPT-5.6 Luna
62%Vocabulary59%
111wSentence Length19w
0.40Hedging0.84
5.0Bold2.7
9.3Lists4.5
0.88Emoji0.00
2.16Headings1.20
0.33Transitions0.10
Based on 17 + 27 text responses
Research
What we learned reading every model
FAQ
