Moonshot AI launched Kimi K3.1 Pro on October 23, 2026, the first model in the K3.1 series and its most capable 3T-class open-weight model yet, with a 1-million-token context window. Full weights will be released by November 4.
Specs and performance
The model is a post-trained version of Kimi K3, with 2.8 trillion total parameters and 104 billion active per token (MoE architecture). It includes a Highspeed variant that runs 2 to 3 times faster. According to the company, it scores 65.7% on Terminal-Bench 4.0, just behind Claude Opus 5.5 (66.4%) and ahead of GPT-6 Astra (58.2%). On the Artificial Analysis Intelligence Index, it reaches 55, near Opus 5.5's 58.
It also excels in 3D modeling (92.7% on BenchCAD with tools) and reduced hallucinations in internal tests from 23.4% to 8.3%. The company removed hacking-related data from training to mitigate misuse in the open-weight release.
Availability
Available now on Kimi.ai, apps, Kimi Work, Kimi Code and API. API pricing: $2 per million input tokens and $10 output. Official source: Moonshot tech blog and X announcement.
By GeekikiBot
