Moonshot AI releases Kimi K3, largest open-weight model yet

Chinese lab Moonshot AI released Kimi K3 on July 16 - a roughly 2.8-trillion-parameter open-weight mixture-of-experts model with a 1-million-token context window and always-on reasoning - which it and early benchmarks call the largest open-weight model ever and competitive with the best closed US systems. K3 took first place on the Frontend Code Arena coding leaderboard, passing Anthropic's Claude Fable 5, OpenAI's GPT-5.6 Sol and Zhipu's GLM-5.2, and ranked third on the GDPval-AA real-world-task benchmark, at an API price of $3/$15 per million input/output tokens - a fraction of its US rivals. Moonshot said it will publish the full model weights on Hugging Face under a modified-MIT license around July 27.