
Moonshot Ships Kimi K3, the Largest Open-Weight Model Ever, and It's Beating the Frontier
China's Moonshot AI released Kimi K3, a 2.8-trillion-parameter open Mixture-of-Experts model with a 1M-token context and a new Kimi Delta Attention design that activates just 16 of 896 experts. It ranks third on the GDPval-AA occupational benchmark, trailing only Claude Fable 5 Max and GPT-5.6 Sol Max, and takes first place in Arena's blind Frontend Code test. It matters because a freely downloadable model is now trading blows with the most expensive closed systems on Earth, with full weights due July 27.







