Moonshot AI's Kimi K3.1 Pro reaches fourth on Artificial Analysis index, 3 points behind Claude Opus 5.5

Moonshot AI introduced Kimi K3.1 Pro on October 24, 2026, along with K3.1 Pro Highspeed, a variant the company says delivers two to three times the base model’s speed with identical capabilities. The models are available through Kimi.ai, iOS, Android and HarmonyOS apps, Kimi Work version 3.1.0 or later, Kimi Code and the Kimi API. API customers can use Zero Data Retention, while Kimi Enterprise administrators can enable access for their organizations; enterprise access is disabled by default at launch. Kimi K3.1 Pro scored 55 on the Artificial Analysis Intelligence Index, placing fourth behind Claude Opus 5.5 at 58, Claude Sonnet 5.5 at 56 and Muse Wonder Full at 56. Its score is 11 points higher than Kimi K3’s. Moonshot plans to publish the model’s full weights by November 4, 2026, which it says would make it the highest-scoring open-weights model on the index. The post-trained Kimi K3 model retains 2.8 trillion total parameters, with 104 billion active parameters, a one-million-token context window, and text-and-image input support. It scored 65.7% on Terminal-Bench 4.0. Moonshot said it outperforms GPT-6 in programming-agent evaluations, and API prices are 33% lower than for Kimi K3.