A Chinese AI startup just dropped the largest open-source AI model ever built. Moonshot AI, the Beijing-based company backed by Alibaba, introduced its Kimi K3 model on July 16, making it available through its API and hosted platforms. The full model weights will be downloadable by anyone on July 27 under a Modified MIT license.
The model packs 2.8 trillion parameters, making it the first publicly available model to crack the 3-trillion-parameter range.
What makes Kimi K3 different
The model uses a mixture-of-experts (MoE) architecture combined with something Moonshot calls Kimi Delta Attention technology. Instead of firing every parameter for every query, the system activates only the most relevant subset of its massive parameter pool, keeping inference costs manageable despite the model’s enormous scale.
Kimi K3 supports 1 million tokens, which means it can process roughly the equivalent of several full-length novels in a single prompt. That’s designed for heavy-duty tasks like long-horizon coding, advanced knowledge work, and deep reasoning.
