Gemini 3.5 Flash vs OpenAI: GPT-5.6 Luna Pro
Compare Gemini 3.5 Flash by Google AI against OpenAI: GPT-5.6 Luna Pro by OpenAI, context windows of 1.0M vs 1.1M, tested across 54 shared challenges.
Our Verdict
Gemini 3.5 Flash
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
Gemini 3.5 Flash
Input
$1.50
Output
$9.00
OpenAI: GPT-5.6 Luna Pro
Input
$1.00
1.5× cheaper
Output
$6.00
1.5× cheaper
OpenAI: GPT-5.6 Luna Pro is cheaper on both — 1.5× input, 1.5× output
Writing DNA
Style Comparison
Similarity
36%
OpenAI: GPT-5.6 Luna Pro uses 53.7x more emoji
Gemini 3.5 Flash
OpenAI: GPT-5.6 Luna Pro
59%Vocabulary58%
18wSentence Length18w
0.16Hedging0.81
4.4Bold2.9
3.0Lists5.1
0.00Emoji0.54
0.89Headings1.10
0.11Transitions0.09
Based on 27 + 27 text responses
Research
What we learned reading every model
FAQ
