Kimi K3 is a 2.8-trillion-parameter model released by Moonshot AI as an open-weight entry into the frontier model tier. Its architecture introduces two named innovations: Kimi Delta Attention and Attention Residuals, which together form the backbone of how the model processes sequences. The combination of this parameter scale and these architectural choices positions it as the first openly available 3T-class model, giving researchers and developers access to a system at a size tier previously reserved for closed proprietary releases.

Kimi K3 targets long-horizon coding, knowledge work, and reasoning, and ships with native vision capabilities alongside a one-the cataloged API limit for handling extended inputs. In Moonshot AI's own evaluation suite, the model demonstrated frontier-level performance and consistently outperformed other tested models, though the company notes its overall results still trail the leading proprietary systems. The weights are publicly hosted on Hugging Face under a dedicated license file, making the model suitable for teams that need a large-scale open foundation for agentic workflows, extended document understanding, and complex multi-step reasoning without dependency on closed APIs.