Claude Opus 4 vs OpenAI: GPT-5.6 Luna
Compare Claude Opus 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 Opus 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.
OpenAI: GPT-5.6 Luna is 13x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
OpenAI: GPT-5.6 Luna
Input
$1.00
15× cheaper
Output
$6.00
13× cheaper
OpenAI: GPT-5.6 Luna is cheaper on both — 15× input, 13× output
Writing DNA
Style Comparison
Similarity
44%
Claude Opus 4 uses 11.2x more emoji
Claude Opus 4
OpenAI: GPT-5.6 Luna
64%Vocabulary59%
62wSentence Length19w
0.52Hedging0.84
4.4Bold2.7
9.1Lists4.5
0.11Emoji0.00
1.87Headings1.20
0.27Transitions0.10
Based on 16 + 27 text responses
Research
What we learned reading every model
FAQ
