Claude Sonnet 4 vs OpenAI: GPT-5.6 Luna Pro
Compare Claude Sonnet 4 by Anthropic against OpenAI: GPT-5.6 Luna Pro by OpenAI, context windows of 200K vs 1.1M, tested across 53 shared challenges.
Our Verdict
Claude Sonnet 4
OpenAI: GPT-5.6 Luna Pro
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 Pro
Input
$1.00
3.0× cheaper
Output
$6.00
2.5× cheaper
OpenAI: GPT-5.6 Luna Pro is cheaper on both — 3.0× input, 2.5× output
Writing DNA
Style Comparison
Similarity
49%
Claude Sonnet 4 uses 6.3x more sentence length
Claude Sonnet 4
OpenAI: GPT-5.6 Luna Pro
62%Vocabulary58%
111wSentence Length18w
0.40Hedging0.81
5.0Bold2.9
9.3Lists5.1
0.88Emoji0.54
2.16Headings1.10
0.33Transitions0.09
Based on 17 + 27 text responses
Research
What we learned reading every model
FAQ
