Kimi K3
Open frontier intelligence with 2.8T parameters and 1M context window
Context window
1M
Input / 1M tokens
$3.00
Output / 1M tokens
$15.00
Provider
Moonshot AI
Data verified 2026-07-18
Kimi K3 is Moonshot AI's flagship large language model, a 2.8-trillion-parameter Mixture-of-Experts model with native multimodal vision capabilities, 1M-token context window, and always-on reasoning mode. It ranks fourth overall among frontier models, trailing only Claude Fable 5 and GPT-5.6 Sol, with particularly strong coding performance.
Capability index
Relative estimates (0-100) to place this model against its peers, grounded in published benchmarks.
How to access it
Available via Kimi API and web interface at kimi.ai. Full open-source weights scheduled for release by July 27, 2026.
Strengths
- ✓1M-token context window for long-horizon tasks
- ✓Superior coding performance - leads Arena.ai Frontend Code benchmark
- ✓2.5x improved scaling efficiency over K2
- ✓Multimodal (text, image, video) capabilities
- ✓Open-weight release planned for July 27, 2026
Best for developers who...
When to choose it (and when not to)
Reach for Kimi K3 when...
- →When you need open-weight frontier-class model with large context
- →For coding-heavy workloads where it outperforms Fable 5
- →When planning to self-host after July 27 release
Look elsewhere if...
- ✕For cost-sensitive quick chat applications
- ✕If you need model weights immediately (not available until July 27)
- ✕If general knowledge tasks are priority over coding
How to use it
- ›Model uses always-on maximum reasoning effort
- ›Supply full context and detailed specifications for best results
- ›Reason tokens are billed as output tokens
Quickstart
Pythonfrom moonshot import MoonshotAPI
client = MoonshotAPI()
response = client.chat.completions.create(
model='kimi-k3',
messages=[{'role': 'user', 'content': 'Your prompt here'}]
)
print(response.choices[0].message.content)Via Kimi API or OpenRouter/third-party providers
API model id: kimi-k3
Benchmarks
| Benchmark | Score | Notes |
|---|---|---|
| Arena.ai Frontend Code | 1679 (ranked #1) | Topped leaderboard within 24 hours of launch |
| Artificial Analysis Intelligence Index | 57 (Elo 1547) | +732 points from K2.6, behind only Fable 5 |
| Cost per task | $0.94 | Similar to GPT-5.6 Sol ($1.04), half of Opus 4.8 ($1.80) |
Source: Artificial Analysis, Arena.ai
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