Claude Opus 4vsKimi K2
Kimi K2 is cheaper than Claude Opus 4 at $0.57/M vs $15/M input tokens.
| Spec | Claude Opus 4 | Kimi K2 |
|---|---|---|
| Input price | $15/M tokens | $0.57/M tokens |
| Output price | $75/M tokens | $2.3/M tokens |
| Context window | 200K tokens | — |
| Weights | Closed | Open |
| Free API (OpenRouter) | No | No |
| Released | May 2025 | Jul 2025 |
| SWE-bench Verified | 72.5% | 65.8% |
Our Verdict
Claude Opus 4
Kimi K2Runner-up
Not enough votes to call it. On the specs, Claude Opus 4 has the edge: bigger context window, major provider backing.
Claude Opus 4 wins Web Design and Image Generation. Kimi K2 costs 33x less per token.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
Kimi K2
Input
$0.57
26× cheaper
Output
$2.30
33× cheaper
Kimi K2 is cheaper on both: 26× input, 33× output.
Where to run it
2 hosts
Claude Opus 41 host
Kimi K21 host
Per million tokens. Prices and uptime via OpenRouter, checked 9 Sep 2026.
Writing DNA
Style Comparison
Similarity
45%
Claude Opus 4 uses 4.4x more transitions
Claude Opus 4
Kimi K2
65%Vocabulary66%
57wSentence Length19w
0.67Hedging0.34
3.8Bold3.3
6.8Lists3.4
1.18Emoji0.54
1.42Headings0.48
0.22Transitions0.05
Based on 27 + 28 text responses
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