Seed-Coder is a series of open-source code large language models launched by the Seed Team of ByteDance. It includes base, instruction, and reasoning models, aiming to significantly enhance programming capabilities through minimal human effort and autonomous management of code training data. The model performs excellently among similar open-source models and is suitable for various coding tasks. It is positioned to promote the development of the open-source LLM ecosystem and is applicable to both research and industry.