Gemini 2.5 Flash Preview vs OpenAI: GPT-5.6 Luna
Compare Gemini 2.5 Flash Preview by Google AI against OpenAI: GPT-5.6 Luna by OpenAI, context windows of 1.0M vs 1.1M, tested across 26 shared challenges.
Our Verdict
Gemini 2.5 Flash Preview
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.
Gemini 2.5 Flash Preview is 10x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Gemini 2.5 Flash Preview
Input
$0.15
6.7× cheaper
Output
$0.60
10× cheaper
OpenAI: GPT-5.6 Luna
Input
$1.00
Output
$6.00
Gemini 2.5 Flash Preview is cheaper on both — 6.7× input, 10× output
Writing DNA
Style Comparison
Similarity
43%
OpenAI: GPT-5.6 Luna uses 13.5x more headings
Gemini 2.5 Flash Preview
OpenAI: GPT-5.6 Luna
51%Vocabulary59%
15wSentence Length19w
0.70Hedging0.84
4.1Bold2.7
3.3Lists4.5
0.00Emoji0.00
0.09Headings1.20
0.24Transitions0.10
Based on 12 + 27 text responses
Research
What we learned reading every model
FAQ
