Gemini 2.5 Flash Preview 05-20 (thinking) vs GPT-5.6 Luna Pro
Compare Gemini 2.5 Flash Preview 05-20 (thinking) by Google AI against GPT-5.6 Luna Pro by OpenAI, context windows of 1.0M vs 1.1M, tested across 11 shared challenges.
Our Verdict
Gemini 2.5 Flash Preview 05-20 (thinking)
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 2.5 Flash Preview 05-20 (thinking)
Input
$0.15
6.7× cheaper
Output
$3.50
1.7× cheaper
GPT-5.6 Luna Pro
Input
$1.00
Output
$6.00
Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper on both — 6.7× input, 1.7× output
Writing DNA
Style Comparison
Similarity
36%
GPT-5.6 Luna Pro uses 80.8x more hedging
Gemini 2.5 Flash Preview 05-20 (thinking)
GPT-5.6 Luna Pro
70%Vocabulary58%
11wSentence Length18w
0.00Hedging0.81
4.2Bold2.9
7.3Lists5.1
0.00Emoji0.54
0.00Headings1.10
0.00Transitions0.09
Based on 3 + 27 text responses
Research
What we learned reading every model
FAQ
