FlashVSR is the first real-time, diffusion-based one-step video super-resolution (VSR) framework, delivering up to 12× faster performance than previous VSR models. It efficiently transforms long videos into high-quality 4K resolution with crisp, detailed, and lifelike visuals. Powered by a three-stage distillation pipeline, sparse attention, and a tiny conditional decoder, FlashVSR achieves exceptional speed and quality in both video upscaling and restoration. This advanced architecture minimizes redundant computation while maintaining visual fidelity, making it ideal for AI video enhancement, content restoration, and high-efficiency 4K video production.