Moonshot AI has launched Kimi K3, a 2.8 trillion-parameter model that is now the world’s largest open-weights AI system. The model has already topped the Frontend Code Arena leaderboard, beating Anthropic’s Claude Fable 5.
Kimi K3 uses a Mixture-of-Experts architecture with a 1 million-token context window. The model targets long-running coding sessions, repository-scale analysis, and agent workflows requiring sustained reasoning. Moonshot released two versions: K3 Max for chat and reasoning, and K3 Swarm Max for orchestrating multiple AI agents working in parallel.
The model’s open weights will be released on July 27. Arena CEO Anastasios Angelopoulos called it “the single biggest release of the year,” suggesting it may represent the moment China has surpassed the US in AI model capabilities. Moonshot claims Kimi K3 is within striking distance of GPT-5.6 Sol in several key benchmarks.
The launch intensifies the open-weight AI race. DeepSeek, Alibaba’s Qwen, and Thinking Machines have all released competitive open models in recent months, driving down inference costs and accelerating global AI adoption.
