Image Sharpener
Crisp up soft photos without colour halos.
Crisp Up a Slightly Soft Photo
A photo that is a touch out of focus, a scan that looks soft, or a picture that lost its bite after resizing can often be rescued with sharpening. Drag the three controls and watch the preview change: Amount sets how strong the effect is, Radius the size of the details it works on, and Threshold leaves smooth areas such as skin and sky alone so they do not turn grainy.
The sharpening is an unsharp mask applied to brightness only, so edges get crisper without the coloured fringes that sharpening every channel produces. Presets cover subtle, standard and strong sharpening and a large-radius “clarity” boost. The download is processed at full resolution.
Key features
- Unsharp mask with amount, radius and threshold.
- Brightness-only sharpening, free of colour halos.
- Live preview with a before/after toggle.
- Four presets, including a clarity boost.
- Full-resolution output as PNG, JPG or WebP.
This tool does its work inside your browser using native Web APIs. The files and text you give it are processed on your device and are not uploaded to our servers.
How to use: Image Sharpener
- Open the photo
Drop a JPG, PNG or WebP onto the box. - Start with a preset
Standard suits most photos; Subtle for portraits. - Fine-tune
Adjust the sliders while watching the preview; tick Show original to compare. - Download
Press Download sharpened image.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Media |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Can it fix a very blurry photo?
It can make a slightly soft photo look focused. A badly blurred or shaken photo has lost the detail, and sharpening mostly exaggerates noise.
What do radius and threshold do?
Radius sets the size of edges that get sharpened — small for fine detail, large for local contrast. Threshold skips areas with little contrast, keeping skin and sky smooth.
Why sharpen brightness only?
Sharpening colour channels separately creates red and green fringes on edges. Working on brightness gives the same crispness without them.
Should I sharpen before or after resizing?
After. Resizing softens an image, so sharpen the final size.
Why does sharpening make noise worse?
Noise is fine detail, so sharpening strengthens it along with the edges. Raise the threshold to protect smooth areas, or lower the amount, when a photo was taken in low light or at a high ISO setting.