LongCat-Flash-Omni Technical Report
Authors: name: Meituan LongCat Team; name: Bairui Wang; name: Bayan; name: Bin Xiao; name: Bo Zhang; name: Bolin Rong; name: Borun Chen; name: Chang Wan; name: Chao Zhang; name: Chen Huang; name: Chen Chen; name: Chen Chen; name: Chengxu Yang; name: Chengzuo Yang; name: Cong Han; name: Dandan Peng; name: Delian Ruan; name: Detai Xin; name: Disong Wang; name: Dongchao Yang; name: Fanfan Liu; name: Fengjiao Chen; name: Fengyu Yang; name: Gan Dong; name: Gang Huang; name: Gang Xu; name: Guanglu Wan; name: Guoqiang Tan; name: Guoqiao Yu; name: Haibo Qiu; name: Hao Lu; name: Hongbo Liu; name: Hongyu Xiang; name: Jiaheng Wu; name: Jian Yang; name: Jiaxing Liu; name: Jing Huang; name: Jingang Wang; name: Jinrui Ding; name: Juchao Jiang; name: Jun Kuang; name: Jun Wang; name: Junhui Mei; name: Ke Ding; name: Kefeng Zhang; name: Lei Chen; name: Liang Shi; name: Limeng Qiao; name: Liming Zheng; name: Lin Ma; name: Liuyang Guo; name: Liya Ma; name: Luying Sun; name: Man Gao; name: Mengshen Zhu; name: Miao Cao; name: Minliang Lin; name: Nuo Xu; name: Peng Shi; name: Qi Zhang; name: Qian Fang; name: Qian Wang; name: Qian Yang; name: Quanxiu Wang; name: Rongxiang Weng; name: Rongxin Guo; name: Ruoxuan Liang; name: Senbin Yang; name: Shanbo Xu; name: Shanglin Lei; name: Shengze Ye; name: Shimin Chen; name: Shuaiqi Chen; name: Shujie Hu; name: Shuo Li; name: Siqi Yang; name: Siyu Xu; name: Siyu Ren; name: Song Li; name: Songxiang Liu; name: Tianhao Bai; name: Tianye Dai; name: Wei Hong; name: Wei Wang; name: Weixiao Zhao; name: Wengang Cao; name: Wenlong Zhu; name: Wenlong He; name: Xi Su; name: Xi Nan; name: Xiaohan Zhao; name: Xiaohao Wang; name: Xiaoyu Zhao; name: Xiaoyu Wang; name: Xiaoyu Li; name: Xin Pan; name: Xin Chen; name: Xiusong Sun; name: Xu Xiang; name: Xudong Xing; name: Xuezhi Cao; name: Xunliang Cai; name: Yang Yang; name: Yanli Tan; name: Yao Yao; name: Yerui Sun; name: Yi Chen; name: Yifan Lu; name: Yin Gong; name: Yining Zhang; name: Yitian Chen; name: Yiyang Gan; name: Yuchen Tang; name: Yuchen Xie; name: Yueqian Wang; name: Yuewen Zheng; name: Yufei Zhang; name: Yufeng Zhong; name: Yulei Qian; name: Yuqi Peng; name: Yuwei Jiang; name: Zeyang Hu; name: Zheng Zhang; name: Zhengkun Tian; name: Zhiqing Hong; name: Zhixiong Zeng; name: Zhuqi Mi; name: Ziran Li; name: Ziwen Wang; name: Ziyi Zhao; name: Ziyuan Zhuang; name: Zizhe Zhao
Published: 2025-10-31 21:58:15

Abstract: We introduce LongCat-Flash-Omni, a state-of-the-art open-source omni-modal
model with 560 billion parameters, excelling at real-time audio-visual
interaction. By adopting a curriculum-inspired progressive training strategy
that transitions from simpler to increasingly complex modality sequence
modeling tasks, LongCat-Flash-Omni attains comprehensive multimodal
capabilities while maintaining strong unimodal capability. Building upon
LongCat-Flash, which adopts a high-performance Shortcut-connected
Mixture-of-Experts (MoE) architecture with zero-computation experts,
LongCat-Flash-Omni integrates efficient multimodal perception and speech
reconstruction modules. Despite its immense size of 560B parameters (with 27B
activated), LongCat-Flash-Omni achieves low-latency real-time audio-visual
interaction. For training infrastructure, we developed a modality-decoupled
parallelism scheme specifically designed to manage the data and model
heterogeneity inherent in large-scale multimodal training. This innovative
approach demonstrates exceptional efficiency by sustaining over 90% of the
throughput achieved by text-only training. Extensive evaluations show that
LongCat-Flash-Omni achieves state-of-the-art performance on omni-modal
benchmarks among open-source models. Furthermore, it delivers highly
competitive results across a wide range of modality-specific tasks, including
text, image, and video understanding, as well as audio understanding and
generation. We provide a comprehensive overview of the model architecture
design, training procedures, and data strategies, and open-source the model to
foster future research and development in the community.