ComfyUI is a free, open-source, node-based graphical user interface (GUI) primarily used for running generative AI models—such as Stable Diffusion, FLUX, SDXL, and advanced video generation frameworks—locally on your own hardware. Unlike traditional tab-based interfaces (like AUTOMATIC1111 or Fooocus) that hide processes behind buttons and sliders, ComfyUI exposes the underlying generative pipeline as a visual flowchart.