UniEdit is a tuning-free framework for video motion and appearance editing, leveraging a pre-trained text-to-video generator within an inversion-then-generation framework. It supports both video motion editing (e.g., changing actions from playing guitar to waving) and various appearance editing scenarios (e.g., stylization, object replacement, background modification). The framework introduces auxiliary motion-reference and reconstruction branches to generate text-guided motion and source features, which are then injected into the main editing path via temporal and spatial self-attention layers. Extensive experiments show that UniEdit outperforms state-of-the-art methods in both motion and appearance editing, demonstrating superior performance in temporal consistency and alignment with text prompts. The framework also supports text-image-to-video generation and is designed to be flexible and efficient, with the ability to preserve source content and control spatial structure during editing. UniEdit is a pioneering approach in text-guided, tuning-free video motion editing, offering a unified architecture for a wide range of video editing tasks.UniEdit is a tuning-free framework for video motion and appearance editing, leveraging a pre-trained text-to-video generator within an inversion-then-generation framework. It supports both video motion editing (e.g., changing actions from playing guitar to waving) and various appearance editing scenarios (e.g., stylization, object replacement, background modification). The framework introduces auxiliary motion-reference and reconstruction branches to generate text-guided motion and source features, which are then injected into the main editing path via temporal and spatial self-attention layers. Extensive experiments show that UniEdit outperforms state-of-the-art methods in both motion and appearance editing, demonstrating superior performance in temporal consistency and alignment with text prompts. The framework also supports text-image-to-video generation and is designed to be flexible and efficient, with the ability to preserve source content and control spatial structure during editing. UniEdit is a pioneering approach in text-guided, tuning-free video motion editing, offering a unified architecture for a wide range of video editing tasks.