Moonshot AI Releases Kimi K3, the World's Largest Open-Source Model

Beijing-based Moonshot AI has launched Kimi K3, a 2.8-trillion-parameter model that is now the world's largest open-source AI model. Designed for complex tasks like software engineering and multimodal research, Kimi K3's performance reportedly rivals top closed-source models like Claude Fable 5 and GPT-5.6 Sol. However, the launch has triggered an immediate computing bottleneck, forcing Moonshot AI to temporarily suspend new consumer subscriptions within 48 hours due to overwhelming demand.

Kimi K3's release shifts the open-source AI landscape, demonstrating that Chinese firms can match or exceed Western rivals in model scale. It provides global developers with a massive, highly capable open-source alternative to proprietary models, potentially accelerating AI democratization while intensifying global competition.

Beijing-based Moonshot AI has released Kimi K3, a new-generation open-source model boasting 2.8 trillion parameters, making it the largest open-source model globally. Released on July 16, 2026, the model marks a significant milestone for China's AI ecosystem, pushing the boundaries of open-source capabilities. According to Moonshot AI, Kimi K3 features native visual understanding and a 1-million-token context window. It is optimized for complex tasks such as software engineering, deep research, and multimodal understanding. In benchmark tests, Kimi K3's overall intelligence reportedly ranks just behind leading closed-source models Claude Fable 5 and GPT-5.6 Sol, showing strong performance in coding and long-context tasks. The release has drawn international attention, including from Elon Musk. Following the announcement, shares of Google's parent Alphabet and Meta fell by 2% and 3% respectively on July 17, with some investors attributing the drop to the competitive pressure from the new Chinese model. Despite its technical success, Moonshot AI is already grappling with severe resource constraints. On July 19, just 48 hours after the launch, the company announced a temporary suspension of new consumer subscriptions. The company cited an overwhelming surge in user requests that neared the limits of its existing server clusters. Moonshot AI stated it is actively expanding its computing power capacity to resume subscriptions gradually.