DAPO: An Open-Source LLM Reinforcement Learning System at Scale

Xin Liu (Peng Cheng Laboratory) · Yuxuan Song (Tsinghua University; Bytedance) · Hao Zhou (Bytedance AI Lab) · Wei-Ying Ma (Tsinghua University) · Jingjing Liu (Microsoft) · Qiying Yu (Tsinghua University) · Zheng Zhang (ByteDance) · Mingxuan Wang (ByteDance Inc.) · Hongli Yu (Harbin Institute of Technology) · Haibin Lin (Bytedance Inc) · Jiangjie Chen (ByteDance Seed) · Chi Zhang (Westlake University) · LingJun Liu (ByteDance Inc.) · Bole Ma (ByteDance Inc.) · Yonghui Wu (Google) · Ruofei Zhu (ByteDance Inc.) · Yufeng Yuan (University of Alberta) · Xiaochen Zuo (ByteDance Inc.) · Yu Yue (Bytedance) · Weinan Dai (Tsinghua University) · Tiantian Fan (ByteDance) · Gaohong Liu (ByteDance Inc.) · juncai liu (ByteDance Inc.) · Zhiqi Lin (ByteDance Inc.) · Guangming Sheng (University of Hong Kong) · Yuxuan Tong (CS & Tech. Dept., Tsinghua Univ.) · Mofan Zhang (ByteDance Inc.) · Ru Zhang (ByteDance Inc.) · Wang Zhang (ByteDance Inc.) · Hang Zhu (ByteDance Inc.) · Jinhua Zhu (University of Science and Technology of China) · Jiaze Chen (Bytedance) · Chengyi Wang (Nankai University) · Xiangpeng Wei (Institute of Information Engineering, Chinese Academy of Sciences) · Ya-Qin Zhang (George Washington University) · Lin Yan (ByteDance Inc.)
curated datasetdapo algorithmdecoupled clipdynamic samplinginference scalinglarge-scale rlpolicy optimizationqwen2.5-32breasoning abilityreinforcement learningreproducibilitytraining codeverl framework

Inference scaling empowers LLMs with unprecedented reasoning ability, with reinforcement learning as the core technique to elicit complex reasoning. However, key technical details of state-of-the-art reasoning LLMs are concealed (such as in OpenAI o1 blog and DeepSeek R1 technical report), thus the community still struggles to reproduce their RL training results. We propose the **D**ecoupled Clip and **D**ynamic s**A**mpling **P**olicy **O**ptimization (**DAPO**) algorithm, and fully open-source a state-of-the-art large-scale RL system that achieves 50 points on AIME 2024 using Qwen2.5-32B base model. Unlike previous works that withhold training details, we introduce four key techniques of our algorithm that make large-scale LLM RL a success. In addition, we open-source our training code, which is built on the verl framework, along with a carefully curated and processed dataset. These components of our open-source system enhance reproducibility and support future research in large-scale LLM RL.