Gemini 2.5 Flash Preview (thinking) vs OpenAI: GPT-5.6 Luna
Compare Gemini 2.5 Flash Preview (thinking) by Google AI against OpenAI: GPT-5.6 Luna by OpenAI, context windows of 1.0M vs 1.1M, tested across 20 shared challenges.
Our Verdict
Gemini 2.5 Flash Preview (thinking)
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.
Too close to call
API pricing
Cost per 1M tokens
Gemini 2.5 Flash Preview (thinking)
Input
$0.17
5.7× cheaper
Output
$3.50
1.7× cheaper
OpenAI: GPT-5.6 Luna
Input
$1.00
Output
$6.00
Gemini 2.5 Flash Preview (thinking) is cheaper on both — 5.7× input, 1.7× output
Writing DNA
Style Comparison
Similarity
33%
OpenAI: GPT-5.6 Luna uses 119.5x more headings
Gemini 2.5 Flash Preview (thinking)
OpenAI: GPT-5.6 Luna
53%Vocabulary59%
14wSentence Length19w
0.38Hedging0.84
4.4Bold2.7
4.1Lists4.5
0.00Emoji0.00
0.00Headings1.20
0.24Transitions0.10
Based on 7 + 27 text responses
Research
What we learned reading every model
FAQ
