Unsharp Mask
Sharpen an image the way photo editors do, with radius, amount and threshold.
Fill in the form and press “Sharpen” to see the result here.
How to use it
- 1Select your image, or drag and drop it onto the upload area.
- 2Adjust the options if you need something other than the defaults.
- 3Press the button. The image is processed on your device - nothing is uploaded.
- 4Download the result, or drop in another file to do it again.
About the Unsharp Mask
An unsharp mask subtracts a blurred copy from the original and adds back the difference, which exaggerates edges. Despite the name, it sharpens.
The threshold is the control that matters most on photographs: without it, sharpening amplifies sensor noise in flat areas such as skies and skin as enthusiastically as it does real detail.
Sharpening cannot recover detail that was never captured. It makes existing edges more prominent, and pushed too far it produces bright halos along them.
Questions people ask
Is your image uploaded to a server?
No. This tool runs entirely in your browser using standard web APIs, so your image never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.
Is it free, and do I need an account?
Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.