China’s Moonshot AI releases Kimi K3, the largest open-source model ever, rivaling top U.S. systems

Beijing-based Moonshot AI released Kimi K3, a 2.8-trillion-parameter model it claims is the world’s largest open-source AI system. The model includes a 1-million-token context window, visual understanding, and always-on reasoning, with full weights expected on July 27.

Kimi K3 signals that Chinese AI labs are pushing open-source models closer to proprietary frontier systems, intensifying competitive pressure on U.S. leaders. If its benchmark claims hold up, the release could accelerate enterprise adoption of open-source AI and reshape expectations around model scale and accessibility.