_version_ 1866918137234980864
author Yang, Biao
Wen, Bin
Ding, Boyang
Liu, Changyi
Chu, Chenglong
Song, Chengru
Rao, Chongling
Yi, Chuan
Li, Da
Zang, Dunju
Yang, Fan
Zhou, Guorui
Zhang, Guowang
Shen, Han
Peng, Hao
Ding, Haojie
Wang, Hao
Fan, Haonan
Ju, Hengrui
Huang, Jiaming
Cao, Jiangxia
Chen, Jiankang
Hua, Jingyun
Chen, Kaibing
Jiang, Kaiyu
Tang, Kaiyu
Gai, Kun
Wei, Muhao
Wang, Qiang
Wang, Ruitao
Na, Sen
Zhang, Shengnan
Mao, Siyang
Huang, Sui
Zhang, Tianke
Gao, Tingting
Chen, Wei
Yuan, Wei
Wu, Xiangyu
Hu, Xiao
Lu, Xingyu
Zhang, Yi-Fan
Yang, Yiping
Chen, Yulong
Lu, Zeyi
Wu, Zhenhua
Ling, Zhixin
Yang, Zhuoran
Li, Ziming
Xu, Di
Gao, Haixuan
Li, Hang
Wang, Jing
Ren, Lejian
Hu, Qigen
Wang, Qianqian
Wang, Shiyao
Luo, Xinchen
Li, Yan
Hu, Yuhang
Zhang, Zixing
author_facet Yang, Biao
Wen, Bin
Ding, Boyang
Liu, Changyi
Chu, Chenglong
Song, Chengru
Rao, Chongling
Yi, Chuan
Li, Da
Zang, Dunju
Yang, Fan
Zhou, Guorui
Zhang, Guowang
Shen, Han
Peng, Hao
Ding, Haojie
Wang, Hao
Fan, Haonan
Ju, Hengrui
Huang, Jiaming
Cao, Jiangxia
Chen, Jiankang
Hua, Jingyun
Chen, Kaibing
Jiang, Kaiyu
Tang, Kaiyu
Gai, Kun
Wei, Muhao
Wang, Qiang
Wang, Ruitao
Na, Sen
Zhang, Shengnan
Mao, Siyang
Huang, Sui
Zhang, Tianke
Gao, Tingting
Chen, Wei
Yuan, Wei
Wu, Xiangyu
Hu, Xiao
Lu, Xingyu
Zhang, Yi-Fan
Yang, Yiping
Chen, Yulong
Lu, Zeyi
Wu, Zhenhua
Ling, Zhixin
Yang, Zhuoran
Li, Ziming
Xu, Di
Gao, Haixuan
Li, Hang
Wang, Jing
Ren, Lejian
Hu, Qigen
Wang, Qianqian
Wang, Shiyao
Luo, Xinchen
Li, Yan
Hu, Yuhang
Zhang, Zixing
contents In recent years, the development of Large Language Models (LLMs) has significantly advanced, extending their capabilities to multimodal tasks through Multimodal Large Language Models (MLLMs). However, video understanding remains a challenging area due to the dynamic and information-dense nature of videos. Existing models struggle with the trade-off between spatial resolution and temporal coverage when processing video content. We present Keye-VL-1.5, which addresses fundamental challenges in video comprehension through three key innovations. First, we introduce a novel Slow-Fast video encoding strategy that dynamically allocates computational resources based on inter-frame similarity, processing key frames with significant visual changes at higher resolution (Slow pathway) while handling relatively static frames with increased temporal coverage at lower resolution (Fast pathway). Second, we implement a progressive four-stage pre-training methodology that systematically extends the model's context length from 8K to 128K tokens, enabling processing of longer videos and more complex visual content. Third, we develop a comprehensive post-training pipeline focusing on reasoning enhancement and human preference alignment, incorporating a 5-step chain-of-thought data construction process, iterative GSPO-based reinforcement learning with progressive prompt hinting for difficult cases, and alignment training. Through extensive evaluation on public benchmarks and rigorous internal human assessment, Keye-VL-1.5 demonstrates significant improvements over existing models, particularly excelling in video understanding tasks while maintaining competitive performance on general multimodal benchmarks.
format Preprint
id arxiv_https___arxiv_org_abs_2509_01563
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Kwai Keye-VL 1.5 Technical Report
Yang, Biao
Wen, Bin
Ding, Boyang
Liu, Changyi
Chu, Chenglong
Song, Chengru
Rao, Chongling
Yi, Chuan
Li, Da
Zang, Dunju
Yang, Fan
Zhou, Guorui
Zhang, Guowang
Shen, Han
Peng, Hao
Ding, Haojie
Wang, Hao
Fan, Haonan
Ju, Hengrui
Huang, Jiaming
Cao, Jiangxia
Chen, Jiankang
Hua, Jingyun
Chen, Kaibing
Jiang, Kaiyu
Tang, Kaiyu
Gai, Kun
Wei, Muhao
Wang, Qiang
Wang, Ruitao
Na, Sen
Zhang, Shengnan
Mao, Siyang
Huang, Sui
Zhang, Tianke
Gao, Tingting
Chen, Wei
Yuan, Wei
Wu, Xiangyu
Hu, Xiao
Lu, Xingyu
Zhang, Yi-Fan
Yang, Yiping
Chen, Yulong
Lu, Zeyi
Wu, Zhenhua
Ling, Zhixin
Yang, Zhuoran
Li, Ziming
Xu, Di
Gao, Haixuan
Li, Hang
Wang, Jing
Ren, Lejian
Hu, Qigen
Wang, Qianqian
Wang, Shiyao
Luo, Xinchen
Li, Yan
Hu, Yuhang
Zhang, Zixing
Computer Vision and Pattern Recognition
In recent years, the development of Large Language Models (LLMs) has significantly advanced, extending their capabilities to multimodal tasks through Multimodal Large Language Models (MLLMs). However, video understanding remains a challenging area due to the dynamic and information-dense nature of videos. Existing models struggle with the trade-off between spatial resolution and temporal coverage when processing video content. We present Keye-VL-1.5, which addresses fundamental challenges in video comprehension through three key innovations. First, we introduce a novel Slow-Fast video encoding strategy that dynamically allocates computational resources based on inter-frame similarity, processing key frames with significant visual changes at higher resolution (Slow pathway) while handling relatively static frames with increased temporal coverage at lower resolution (Fast pathway). Second, we implement a progressive four-stage pre-training methodology that systematically extends the model's context length from 8K to 128K tokens, enabling processing of longer videos and more complex visual content. Third, we develop a comprehensive post-training pipeline focusing on reasoning enhancement and human preference alignment, incorporating a 5-step chain-of-thought data construction process, iterative GSPO-based reinforcement learning with progressive prompt hinting for difficult cases, and alignment training. Through extensive evaluation on public benchmarks and rigorous internal human assessment, Keye-VL-1.5 demonstrates significant improvements over existing models, particularly excelling in video understanding tasks while maintaining competitive performance on general multimodal benchmarks.
title Kwai Keye-VL 1.5 Technical Report
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2509.01563