Moonshot AI Releases Kimi K3.1 Pro, Model Weights to Be Open-Sourced by November 4

October 24: According to Moonshot AI's official blog, Moonshot AI has released Kimi K3.1 Pro, the first model in the K3.1 series, along with the high-speed version Kimi K3.1 Pro Highspeed, which runs 2 to 3 times faster than the standard version. Both models support a 1-million-token context. Official data shows that K3.1 Pro scored 65.70% on Terminal-Bench 4.0, higher than GPT-6 Astra's 58.20% and slightly lower than Claude Opus 5.5's 66.40%; in an internal hallucination test, the hallucination rate for individual statements fell from 23.40% with K3 to 8.30%. The new models are now available on Kimi.ai, Kimi Work, Kimi Code and via API, and the full model weights are planned to be released by November 4.