Image Upscaler
Upscale images 2× locally with the Swin2SR lightweight model.
How it works
- 1Select an image — it is loaded directly into your browser, never uploaded.
- 2The long edge is scaled to 512 px or less and snapped to the model's 8-px grid.
- 3The Swin2SR 2× model (~21 MB, downloaded once and cached) runs on WASM in a Web Worker.
- 4Compare the 2× result with the original, then download it as a PNG.
FAQ
Are my images uploaded to a server?
No. Upscaling runs entirely inside your browser. Your image never leaves your device.
Why is my large image resized first?
The pass is capped at a 512 px long edge so a single inference stays within a reasonable time on WASM — tens of seconds to a couple of minutes depending on your device. The output is still 2× the processed input.
What is Swin2SR good at?
Swin2SR excels at classical 2× super-resolution: sharper text, edges and repetitive detail in screenshots, scans and compressed photos. It is not a generative model, so it will not invent missing detail.
Why download a model the first time?
The quantized Swin2SR model (~21 MB) is served from this site and cached by your browser. Later runs start instantly.