Moonshot AI releases Kimi K3.1 Pro, with open weights due by November 4
Moonshot AI released Kimi K3.1 Pro, a multimodal mixture-of-experts model with 2.8 trillion total and 104 billion active parameters and a 1-million-token context window, available now in Kimi's apps and API, with full open weights promised by November 4, 2026.
What happened
- On October 23, 2026, Moonshot AI introduced Kimi K3.1 Pro, a post-trained version of Kimi K3 that it calls its most capable 3T-class open-weight model.
- Moonshot lists 2.8T total and 104B active parameters (mixture of experts), multimodal input and a 1-million-token context window, plus a Highspeed version it says runs 2-3x faster.
- Both are available on Kimi.com, the Kimi apps, Kimi Work, Kimi Code and the Kimi API, and Moonshot says the full model weights will be released by November 4, 2026.
- Moonshot reports 65.7% on Terminal-Bench 4.0, ahead of GPT-6 Astra (58.2%) and just behind Claude Opus 5.5 (66.4%), and highlights coding in Unity, Unreal Engine and Godot plus 3D modeling in Blender and CAD.
- Moonshot also says it identified and removed cyber-related training data and applied targeted controls during training to reduce misuse risk, and launched 3D Make on kimi.com for 3D-printable models.
Why it matters: An open-weight model that Moonshot reports is close to the top closed models on coding gives businesses another option they can eventually run on their own hardware or through lower-cost hosts, though the benchmark figures are Moonshot's own.
Sources
- Kimi K3.1 Pro tech blog kimi.com
- Kimi.ai announcement on X x.com
Checked October 24, 2026 against the sources above. Claims about performance or benchmarks are the company's own unless stated otherwise.