Gemini 3.1 Pro PreviewvsKimi K2.5
Kimi K2.5 is cheaper than Gemini 3.1 Pro Preview at $0.6/M vs $2/M input tokens.
| Spec | Gemini 3.1 Pro Preview | Kimi K2.5 |
|---|---|---|
| Input price | $2/M tokens | $0.6/M tokens |
| Output price | $12/M tokens | $3/M tokens |
| Context window | 1.0M tokens | 262K tokens |
| Weights | Closed | Open |
| Free API (OpenRouter) | No | No |
| Released | Feb 2026 | Jan 2026 |
| SWE-bench Verified | 80.6% | 76.8% |
Our Verdict
Gemini 3.1 Pro Preview
Kimi K2.5Runner-up
Not enough votes to call it. On the specs, Gemini 3.1 Pro Preview has the edge: bigger model tier, bigger context window, major provider backing.
Kimi K2.5 costs 4.0x less per token.
Slight edge
Reviewing agent-written code?See a Brief PR report
API pricing
Cost per 1M tokens
Gemini 3.1 Pro Preview
Input
$2.00
Output
$12.00
Kimi K2.5
Input
$0.60
3.3× cheaper
Output
$3.00
4.0× cheaper
Kimi K2.5 is cheaper on both: 3.3× input, 4.0× output.
Where to run it
8 hosts, cheapest first
Gemini 3.1 Pro Preview2 hosts
Per million tokens. Prices and uptime via OpenRouter, checked 11 Sep 2026.
Writing DNA
Style Comparison
Similarity
54%
Gemini 3.1 Pro Preview
Kimi K2.5
54%Vocabulary62%
18wSentence Length22w
0.29Hedging0.50
4.9Bold4.2
3.3Lists2.4
0.00Emoji0.01
0.72Headings0.51
0.14Transitions0.17
Based on 23 + 26 text responses
Research
What we learned reading every model
FAQ
Common questions
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