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arXiv · 2511.00279

LongCat-Flash-Omni Technical Report

Meituan LongCat Team·Bairui Wang·Bayan·Bin Xiao·Bo Zhang·Bolin Rong·Borun Chen·Chang Wan·Chao Zhang·Chen Huang·Chen Chen·Chengxu Yang·Chengzuo Yang·Cong Han·Dandan Peng·Delian Ruan·Detai Xin·Disong Wang·Dongchao Yang·Fanfan Liu·Fengjiao Chen·Fengyu Yang·Gan Dong·Gang Huang·Gang Xu·Guanglu Wan·Guoqiang Tan·Guoqiao Yu·Haibo Qiu·Hao Lu·Hongbo Liu·Hongyu Xiang·Jiaheng Wu·Jian Yang·Jiaxing Liu·Jing Huang·Jingang Wang·Jinrui Ding·Juchao Jiang·Jun Kuang·Jun Wang·Junhui Mei·Ke Ding·Kefeng Zhang·Lei Chen·Liang Shi·Limeng Qiao·Liming Zheng·Lin Ma·Liuyang Guo·Liya Ma·Luying Sun·Man Gao·Mengshen Zhu·Miao Cao·Minliang Lin·Nuo Xu·Peng Shi·Qi Zhang·Qian Fang·Qian Wang·Qian Yang·Quanxiu Wang·Rongxiang Weng·Rongxin Guo·Ruoxuan Liang·Senbin Yang·Shanbo Xu·Shanglin Lei·Shengze Ye·Shimin Chen·Shuaiqi Chen·Shujie Hu·Shuo Li·Siqi Yang·Siyu Xu·Siyu Ren·Song Li·Songxiang Liu·Tianhao Bai·Tianye Dai·Wei Hong·Wei Wang·Weixiao Zhao·Wengang Cao·Wenlong Zhu·Wenlong He·Xi Su·Xi Nan·Xiaohan Zhao·Xiaohao Wang·Xiaoyu Zhao·Xiaoyu Wang·Xiaoyu Li·Xin Pan·Xin Chen·Xiusong Sun·Xu Xiang·Xudong Xing·Xuezhi Cao
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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.

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Meituan LongCat Team, Bairui Wang, Bayan, Bin Xiao, Bo Zhang, Bolin Rong, Borun Chen, Chang Wan, Chao Zhang, Chen Huang, Chen Chen, Chengxu Yang, Chengzuo Yang, Cong Han, Dandan Peng, Delian Ruan, Detai Xin, Disong Wang, Dongchao Yang, Fanfan Liu, Fengjiao Chen, Fengyu Yang, Gan Dong, Gang Huang, Gang Xu, Guanglu Wan, Guoqiang Tan, Guoqiao Yu, Haibo Qiu, Hao Lu, Hongbo Liu, Hongyu Xiang, Jiaheng Wu, Jian Yang, Jiaxing Liu, Jing Huang, Jingang Wang, Jinrui Ding, Juchao Jiang, Jun Kuang, Jun Wang, Junhui Mei, Ke Ding, Kefeng Zhang, Lei Chen, Liang Shi, Limeng Qiao, Liming Zheng, Lin Ma, Liuyang Guo, Liya Ma, Luying Sun, Man Gao, Mengshen Zhu, Miao Cao, Minliang Lin, Nuo Xu, Peng Shi, Qi Zhang, Qian Fang, Qian Wang, Qian Yang, Quanxiu Wang, Rongxiang Weng, Rongxin Guo, Ruoxuan Liang, Senbin Yang, Shanbo Xu, Shanglin Lei, Shengze Ye, Shimin Chen, Shuaiqi Chen, Shujie Hu, Shuo Li, Siqi Yang, Siyu Xu, Siyu Ren, Song Li, Songxiang Liu, Tianhao Bai, Tianye Dai, Wei Hong, Wei Wang, Weixiao Zhao, Wengang Cao, Wenlong Zhu, Wenlong He, Xi Su, Xi Nan, Xiaohan Zhao, Xiaohao Wang, Xiaoyu Zhao, Xiaoyu Wang, Xiaoyu Li, Xin Pan, Xin Chen, Xiusong Sun, Xu Xiang, Xudong Xing, Xuezhi Cao. 2025-10-31. LongCat-Flash-Omni Technical Report. https://arxiv.org/abs/2511.00279

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