Kimi K3.1 Pro
Moonshot AI · 2026-10-24
Kimi K3.1 Pro is the first model in Moonshot AI's K3.1 series, released on October 24, 2026 (Beijing time) as a post-trained version of Kimi K3 with substantially larger reinforcement-learning compute across hundreds of downstream domains. Moonshot calls it its most capable 3T-class open-weight model, with a 1-million-token context window, and serves it at launch through Kimi.com, Kimi Work, Kimi Code and the Kimi API as kimi-k3.1-pro, alongside a separately named Kimi K3.1 Pro Highspeed endpoint (kimi-k3.1-pro-highspeed) said to run 2-3x faster. Launch results use max reasoning effort with temperature 1.0 and top-p 0.95, and the API documents low, high and max reasoning effort. Moonshot says it removed cyber-related data from mid-training and RL for the open-weight release and will publish the full weights by November 4, 2026; it has not yet released them, a license or an exact parameter count.