Moonshot AI releases Kimi K3.1 Pro, an open-weight model at the edge of the frontier

Moonshot AI released Kimi K3.1 Pro on October 23, 2026. The model has 2.8 trillion total parameters with 104 billion active, a mixture of experts design, and a 1 million token context window. It is live now in the Kimi apps and on the API at $2 per million input tokens and $10 per million output tokens, with a Highspeed variant that Moonshot says runs two to three times faster. Moonshot says the full weights will be released by November 4, 2026. Artificial Analysis independently scores the model 55 on its Intelligence Index, fourth overall. Moonshot's own figures put it at 65.7 percent on Terminal-Bench 4.0, just behind Claude Opus 5.5 at 66.4 percent, and well behind on science reasoning, at 38.1 against 68.1 for GPT-6 Astra.

Moonshot says it removed cyber related data from mid training and reinforcement learning for the open weight release, which cut its internal offensive cyber score from 90.5 percent to 81.0 percent. The benchmark figures other than the Artificial Analysis index score are Moonshot's own and have not been independently checked.

Sources: MarkTechPost; The Decoder; MadRobot