Gemini 2.5 Flash PreviewvsGemini 3.1 Pro Preview
Gemini 2.5 Flash Preview is cheaper than Gemini 3.1 Pro Preview at $0.15/M vs $2/M input tokens.
| Spec | Gemini 2.5 Flash Preview | Gemini 3.1 Pro Preview |
|---|---|---|
| Input price | $0.15/M tokens | $2/M tokens |
| Output price | $0.6/M tokens | $12/M tokens |
| Context window | 1.0M tokens | 1.0M tokens |
| Released | Apr 2025 | Feb 2026 |
| SWE-bench Verified | 60.4% | 80.6% |
Our Verdict
Gemini 3.1 Pro Preview
Gemini 2.5 Flash PreviewRunner-up
Not enough votes to call it. On the specs, Gemini 3.1 Pro Preview has the edge: bigger model tier, newer.
Gemini 2.5 Flash Preview costs 20x less per token.
Too close to call
API pricing
Cost per 1M tokens
Gemini 2.5 Flash Preview
Input
$0.15
13× cheaper
Output
$0.60
20× cheaper
Gemini 3.1 Pro Preview
Input
$2.00
Output
$12.00
Gemini 2.5 Flash Preview is cheaper on both — 13× input, 20× output
Writing DNA
Style Comparison
Similarity
62%
Gemini 3.1 Pro Preview uses 8.1x more headings
Gemini 2.5 Flash Preview
Gemini 3.1 Pro Preview
51%Vocabulary54%
15wSentence Length18w
0.70Hedging0.29
4.1Bold4.9
3.3Lists3.3
0.00Emoji0.00
0.09Headings0.72
0.24Transitions0.14
Based on 12 + 23 text responses
Research
What we learned reading every model
FAQ
Common questions
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