Gemini 2.5 Flash Preview 09-2025 vs GPT-5.6 Luna
Compare Gemini 2.5 Flash Preview 09-2025 by Google AI against GPT-5.6 Luna by OpenAI, context windows of 1.0M vs 1.1M, tested across 50 shared challenges.
Our Verdict
Gemini 2.5 Flash Preview 09-2025
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
Gemini 2.5 Flash Preview 09-2025
Input
$0.30
3.3× cheaper
Output
$2.50
2.4× cheaper
GPT-5.6 Luna
Input
$1.00
Output
$6.00
Gemini 2.5 Flash Preview 09-2025 is cheaper on both — 3.3× input, 2.4× output
Writing DNA
Style Comparison
Similarity
48%
Gemini 2.5 Flash Preview 09-2025 uses 13.5x more emoji
Gemini 2.5 Flash Preview 09-2025
GPT-5.6 Luna
53%Vocabulary59%
19wSentence Length19w
0.30Hedging0.84
5.8Bold2.7
3.1Lists4.5
0.14Emoji0.00
0.93Headings1.20
0.22Transitions0.10
Based on 22 + 27 text responses
Research
What we learned reading every model
FAQ
