# Kimi K3.1 Pro is released as a 3T-class open-weight multimodal model

> Original title: TL;DR

- Source: Sophia Yang
- Published: 2026-10-23T17:41:52.000Z
- Bad Influence: https://badinfluence.news/items/phh2rqukh2k6rwxhwr39e3y3e
- Original: https://x.com/sophiamyang/status/2113687363280879652

## Summary

Sophia Yang reposts Moonshot AI's announcement of Kimi K3.1 Pro, a 3T-class open-weight model with a 1M-token context and 2.8T total and 104B active MoE parameters. Moonshot says it is live on Kimi.ai, Kimi Work, Kimi Code, and the Kimi API, with open weights promised by Nov 4, 2026. The announcement claims strong coding and finance results and a 65% drop in hallucination, with API pricing at $2 input and $10 output per 1M tokens.

## Post

TL;DR 

- MOE 2.8T total and 104B active parameters, 1M context window
- it's probably the same architecture as K3 (Kimi Delta Attention plus gated MLA, with native MXFP4 weights). 
- training: performance gains are from large-scale RL across hundreds of domains, with the focus areas in full-project game-engine coding, 3D and CAD work in Blender, and finance.
- coding: 65.7% on Terminal-Bench 4.0, against 66.4% for Opus 5.5 and 58.2% for GPT-6 Astra. leads SWE Marathon with 51.7, ahead of Opus 5.5 at 46.3.
- agentic: top of the chart on OfficeQA Pro v2 (64.4), Agents' Last Exam (43.2), HLE with tools (70.0) and BrowseComp (92.1). falls well behind on Terminal-Bench Science (38.1 vs 68.1), ProgramBench, and HLE without tools.
- against open peers: beats DeepSeek-V4.1-Flash and GLM-5.3 on every chart in the summary image, but DeepSeek beats it on DeepSWE (77.0 vs 75.5). 
- hallucination: on Moonshot's internal test, the hallucination rate fell from 23.4% on K3 to 8.3%. GPT-6 Astra scores 5.5 on the same test.
- cyber safety: cyber-related data was removed from training for the open-weight release. That lowers its score on Moonshot's exploit test from 90.5% to 81.0%, which is still far above K3's 33.3%.
- price: $2 input and $10 output per 1M tokens, with cached input at $0.20. two-thirds of K3's price. 
- open weights by Nov 4, 2026

## Quoted post @Kimi_Moonshot

> Introducing Kimi K3.1 Pro: our most capable 3T-class open-weight model.
> 
> 🔹 1M-token context, 2.8T total / 104B active params (MoE), Multimodal.
> 🔹 Full-project coding: games in Unreal, Unity & Godot.
> 🔹 Excels at parametric 3D modeling in Blender & CAD.
> 🔹 More reliable at finance work: Accurate modeling with hallucination down by 65%.
> 🔹 Matching the strongest proprietary models across coding, agentic and knowledge benchmarks.
> 
> Kimi K3.1 Pro and K3.1 Pro Highspeed (2–3× faster) are now live on http://Kimi.ai, Kimi Work, Kimi Code, and the Kimi API.  
> 
> Open weights by Nov 4, 2026.
> 
> 🔗 API: http://platform.kimi.ai 
> 🔗 Tech blog: http://kimi.ai/blog/kimi-k3-1-pro

https://x.com/Kimi_Moonshot/status/2113680701770068067