Upscayl

Upscayl is a desktop application (Windows, macOS, Linux) that uses advanced AI models (such as Real-ESRGAN) to upscale and enhance low-resolution images without simply enlarging pixels. It enables users to batch process images, choose from different model styles, preserve color and detail, work entirely offline (if desired), and output high-quality results—even for large resolutions. Features include double upscaling (2× then again), custom width settings, side-by-side before/after comparison, and support for large image sets. Because it’s open-source (AGPL-3.0) and free to use, it’s popular among creators, designers, and developers who want high-quality results without paying for proprietary tools. Users highlight its performance and flexibility, provided you have a reasonably capable GPU (Vulkan compatible) for best results.