GPT-5.1vsKimi K2
Kimi K2 is cheaper than GPT-5.1 at $0.57/M vs $1.25/M input tokens.
| Spec | GPT-5.1 | Kimi K2 |
|---|---|---|
| Input price | $1.25/M tokens | $0.57/M tokens |
| Output price | $10/M tokens | $2.3/M tokens |
| Context window | 400K tokens | — |
| Released | Nov 2025 | Jul 2025 |
| SWE-bench Verified | 76.3% | 65.8% |
Our Verdict
GPT-5.1
Kimi K2Runner-up
Not enough votes to call it. On the specs, GPT-5.1 has the edge: newer, bigger context window, major provider backing.
Kimi K2 costs 4.3x less per token.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1
Input
$1.25
Output
$10.00
Kimi K2
Input
$0.57
2.2× cheaper
Output
$2.30
4.3× cheaper
Kimi K2 is cheaper on both — 2.2× input, 4.3× output
Writing DNA
Style Comparison
Similarity
49%
Kimi K2 uses 68.5x more emoji
GPT-5.1
Kimi K2
62%Vocabulary63%
19wSentence Length19w
0.29Hedging0.35
3.5Bold4.2
7.2Lists3.6
0.00Emoji0.68
0.61Headings0.61
0.03Transitions0.06
Based on 14 + 22 text responses
Research
What we learned reading every model
FAQ
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