Qwen3 foundation models are a family of open-weight large language and multimodal models developed by Alibaba Cloud that serve as versatile base architectures for a broad range of artificial intelligence applications. Pre-trained on extensive multilingual datasets spanning trillions of tokens, these models are designed in multiple parameter scales using both dense and mixture-of-experts architectures. They incorporate hybrid reasoning capabilities that allow dynamic operation between standard direct text generation and extended multi-step reasoning for complex tasks such as coding, mathematics, and logical deduction. In addition to conversational and general generative uses, Qwen3 foundation models serve as foundational backbones and data synthesis engines for specialized downstream adaptations, including text embedding, cross-lingual information retrieval, reranking, autonomous agent workflows, and multimodal understanding across text, vision, and audio.