The best 1080p to 4K upscaler depends on your needs, but UniFab Video Upscaler AI consistently delivers the highest quality results thanks to its four specialized AI models. Other leading tools include Topaz Video AI for pro-level clarity, VideoProc AI for budget users, Premiere Pro for editing workflows, and TensorPix for browser-based online upscaling. This guide compares the top 10 tools with detailed tests, use-case recommendations, and sample outputs.