About & licenses

Image Upscaler is a free browser tool that enlarges pictures up to 4x using an AI super-resolution model running entirely on your device. There is no backend that processes images - the site only serves static files and ads.

How it works

Your browser downloads a 4.6 MB ONNX model (Real-ESRGAN general x4v3) once, then runs tiled inference locally via WebAssembly. Tiles are blended with overlapping margins to avoid seams. Output is a lossless PNG you download directly.

Open-source licenses

• Real-ESRGAN / realesr-general-x4v3 - xinntao/Real-ESRGAN, BSD-3-Clause License. (c) Xintao Wang et al. Used and credited as required by the license.
• ONNX Runtime Web - microsoft/onnxruntime, MIT License. (c) Microsoft Corporation.

Contact

Questions or bug reports: see the contact page.