News · 2026-10-24

Moonshot ships Kimi K3.1 Pro, its most capable open-weight model, with full weights due 4 November

Moonshot AI released Kimi K3.1 Pro on 23 October 2026, the first model in its K3.1 series, alongside a Highspeed variant it says runs two to three times faster. Moonshot calls it the most capable 3T-class open-weight model to date: a post-trained version of Kimi K3 (2.8 trillion total parameters, roughly 104 billion active per Artificial Analysis) with a 1-million-token context window. It is live today in Kimi's apps, Kimi Code and the Kimi API (listed at $2 per million input and $10 per million output tokens, about a third below Kimi K3), with full model weights promised by 4 November 2026. Moonshot reports 65.7% on Terminal-Bench 4.0, ahead of GPT-6 Astra at 58.2% and just behind Claude Opus 5.5 at 66.4%; Artificial Analysis independently scores it 55 on its index, which would make it the highest-scoring open-weight model once weights land. The open-weight version deliberately caps cyber capability: Moonshot says it removed cyber-related data from mid-training and RL, scoring 81% on its internal exploit benchmark versus 90.5% for the uncapped checkpoint.