Sharpen an image

Sharpen one or more images using an unsharp mask, the standard technique used by professional editing software.

Example:
Drag and drop your photos here, or click to choose25 MB max per file

How it works

A photo that's slightly blurry after resizing, or a scan that lacks crispness? Adjust the radius and threshold, then the tool applies an unsharp mask: it compares the image to a blurred version of itself and enhances the differences (the edges), which visually reinforces the perceived sharpness.

What do the radius and threshold control?

The radius (sigma) determines the width of the edges taken into account for sharpening: a low value targets fine details, a high value enhances broader transitions. The threshold defines the minimum brightness difference required for an edge to be enhanced, which helps avoid amplifying noise in flat areas.

Can you over-sharpen an image?

Yes, too high a radius or intensity creates visible halos around edges and an artificial look. It's generally best to start with moderate values and adjust gradually.

100% local processing: the sharpening is performed in your browser via our WebAssembly module — your images are never sent to a server.