MiMo-V2-Flash Technical Report
Authors: name: Bangjun Xiao, name: Bingquan Xia, name: Bo Yang, name: Bofei Gao, name: Bowen Shen, name: Chen Zhang, name: Chenhong He, name: Chiheng Lou, name: Fuli Luo, name: Gang Wang, name: Gang Xie, name: Hailin Zhang, name: Hanglong Lv, name: Hanyu Li, name: Heyu Chen, name: Hongshen Xu, name: Houbin Zhang, name: Huaqiu Liu, name: Jiangshan Duo, name: Jianyu Wei, name: Jiebao Xiao, name: Jinhao Dong, name: Jun Shi, name: Junhao Hu, name: Kainan Bao, name: Kang Zhou, name: Lei Li, name: Liang Zhao, name: Linghao Zhang, name: Peidian Li, name: Qianli Chen, name: Shaohui Liu, name: Shihua Yu, name: Shijie Cao, name: Shimao Chen, name: Shouqiu Yu, name: Shuo Liu, name: Tianling Zhou, name: Weijiang Su, name: Weikun Wang, name: Wenhan Ma, name: Xiangwei Deng, name: Bohan Mao, name: Bowen Ye, name: Can Cai, name: Chenghua Wang, name: Chengxuan Zhu, name: Chong Ma, name: Chun Chen, name: Chunan Li, name: Dawei Zhu, name: Deshan Xiao, name: Dong Zhang, name: Duo Zhang, name: Fangyue Liu, name: Feiyu Yang, name: Fengyuan Shi, name: Guoan Wang, name: Hao Tian, name: Hao Wu, name: Heng Qu, name: Hongfei Yi, name: Hongxu An, name: Hongyi Guan, name: Xing Zhang, name: Yifan Song, name: Yihan Yan, name: Yihao Zhao, name: Yingchun Lai, name: Yizhao Gao, name: Yu Cheng, name: Yuanyuan Tian, name: Yudong Wang, name: Zhen Tang, name: Zhengju Tang, name: Zhengtao Wen, name: Zhichao Song, name: Zhixian Zheng, name: Zihan Jiang, name: Jian Wen, name: Jiarui Sun, name: Jiawei Li, name: Jinlong Xue, name: Jun Xia, name: Kai Fang, name: Menghang Zhu, name: Nuo Chen, name: Qian Tu, name: Qihao Zhang, name: Qiying Wang, name: Rang Li, name: Rui Ma, name: Shaolei Zhang, name: Shengfan Wang, name: Shicheng Li, name: Shuhao Gu, name: Shuhuai Ren, name: Sirui Deng, name: Tao Guo, name: Tianyang Lu, name: Weiji Zhuang, name: Weikang Zhang, name: Weimin Xiong, name: Wenshan Huang, name: Wenyu Yang, name: Xin Zhang, name: Xing Yong, name: Xu Wang, name: Xueyang Xie, name: Yilin Jiang, name: Yixin Yang, name: Yongzhe He, name: Yu Tu, name: Yuanliang Dong, name: Yuchen Liu, name: Yue Ma, name: Yue Yu, name: Yuxing Xiang, name: Zhaojun Huang, name: Zhenru Lin, name: Zhipeng Xu, name: Zhiyang Chen, name: Zhonghua Deng, name: Zihan Zhang, name: Zihao Yue
Organization: Xiaomi MiMo

We present MiMo-V2-Flash, a Mixture-of-Experts (MoE) model with 309B total parameters and 15B active parameters, designed for fast, strong reasoning and agentic capabilities. MiMo-V2-Flash adopts a hybrid attention architecture that interleaves Sliding Window Attention (SWA) with global attention, with a 128-token sliding window under a 5:1 hybrid ratio. The model is pre-trained on 27 trillion tokens with Multi-Token Prediction (MTP), employing a native 32k context length and subsequently extended to 256k. To efficiently scale post-training compute, MiMo-V2-Flash introduces a novel Multi-Teacher On-Policy Distillation (MOPD) paradigm. In this framework, domain-specialized teachers (e.g., trained via large-scale reinforcement learning) provide dense and token-level reward, enabling the student model to perfectly master teacher expertise. MiMo-V2-Flash rivals top-tier open-weight models such as DeepSeek-V3.2 and Kimi-K2, despite using only 1/2 and 1/3 of their total parameters, respectively. During inference, by repurposing MTP as a draft model for speculative decoding, MiMo-V2-Flash achieves up to 3.6 acceptance length and 2.6x decoding speedup with three MTP layers. We open-source both the model weights and the three-layer MTP weights to foster open research and community collaboration.