On July 27, 2026 — eleven days after its soft launch — Moonshot AI released the full Kimi K3 package: open weights, a 47-page technical report, and infrastructure code. The headline number is real: 2.8 trillion parameters, making K3 the world’s first open 3T-class model.
What shipped
| Component | Details |
|---|---|
| Architecture | 2.8T MoE, 104B active per forward pass |
| Context | 1M tokens |
| Weights | Full precision on Hugging Face |
| Technical report | 47 pages on arXiv |
| Infrastructure | Training and inference code on GitHub |
| API pricing | $3 input / $15 output per 1M tokens |
| License | Kimi K3 License (custom — not MIT, not Apache) |
The license caveat
K3 does not ship under MIT or Apache 2.0. The Kimi K3 License permits commercial use but includes restrictions — read the full text before building on it. This matters because the open-weight field has been trending toward genuinely permissive licenses (MIT for GLM-5.2, Apache 2.0 for Inkling), and K3’s custom terms are a step back from that trend.
The hardware caveat
2.8T parameters with 104B active means self-hosting K3 requires 64+ GPUs even with quantization. This is not a “download and run” model — it’s an infrastructure project. For most teams, the API at $3/$15 is the practical route.
Why it matters
- The open-weight ceiling tripled. The previous largest open model was around 1T (Kimi K2.7). K3 at 2.8T demonstrates that China’s AI labs are willing to open truly massive models — even if the license is custom.
- Full transparency is the real story. The 47-page technical report and infrastructure code go beyond weight dumps. Teams can study the architecture, reproduce training decisions, and adapt the inference pipeline — a level of openness rare at this scale.
- Practical access is still the API. Despite being “open,” K3’s hardware requirements put self-hosting out of reach for all but the largest teams. The API at $3/$15 — cheaper than Claude Opus 5 ($5/$25) but without the frontier benchmarks — is how most people will use it.
Full specs, benchmarks and license details: Kimi K3 model page. For the soft-launch story: Kimi K3 soft launch. For landscape context, see the 2026 LLM guide.