Gemini 2.5 Flash Preview 05-20 (thinking) vs Gemini 3.1 Pro Preview
Compare Gemini 2.5 Flash Preview 05-20 (thinking) and Gemini 3.1 Pro Preview, both from Google AI, context windows of 1.0M vs 1.0M, tested across 11 shared challenges.
Our Verdict
Gemini 3.1 Pro Preview
Gemini 2.5 Flash Preview 05-20 (thinking)Runner-up
No community votes yet. On paper, Gemini 3.1 Pro Preview has the edge — bigger model tier, newer.
Gemini 2.5 Flash Preview 05-20 (thinking) is 3.4x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Gemini 2.5 Flash Preview 05-20 (thinking)
Input
$0.15
13× cheaper
Output
$3.50
3.4× cheaper
Gemini 3.1 Pro Preview
Input
$2.00
Output
$12.00
Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper on both — 13× input, 3.4× output
Writing DNA
Style Comparison
Similarity
53%
Gemini 3.1 Pro Preview uses 28.9x more hedging
Gemini 2.5 Flash Preview 05-20 (thinking)
Gemini 3.1 Pro Preview
70%Vocabulary54%
11wSentence Length18w
0.00Hedging0.29
4.2Bold4.9
7.3Lists3.3
0.00Emoji0.00
0.00Headings0.72
0.00Transitions0.14
Based on 3 + 23 text responses
Research
What we learned reading every model
FAQ
