Image Sharpener

Give a slightly soft photo more bite using the same unsharp-mask technique that photo editors use. Amount controls the strength, radius the size of the details that are enhanced, and threshold protects smooth areas such as skin and sky from becoming grainy. Compare the original and the sharpened picture side by side before you download.

Image Editing Runs in your browser

Sharpen Your Image

JavaScript is required. This tool runs in your browser, so please enable JavaScript to use it. The instructions below are still available.

Image

Drag and drop your image (JPG, PNG, WebP, GIF or BMP) here, or click to browseAccepted: JPG, JPEG, PNG, WEBP, GIF, BMP, AVIF. Up to 40 MB.

Amount How strongly edges are boosted.

Radius Size of the details that get sharpened.

Threshold Ignore differences smaller than this, to avoid sharpening noise.

Output format

Quality Used for JPEG and WebP. Higher means a larger file.

Background colourFills transparent areas when the result is saved as JPEG.

How to Use the Image Sharpener

Add your picture.
Start with Amount 100%, Radius 1–2 px and a small Threshold.
Increase the amount until edges look crisp but not haloed, and raise the threshold if noise appears.
Press Sharpen and download the full-resolution result.

About This Tool

Photographers finishing pictures for the web, sellers whose product shots look soft, and anyone sharpening an image after resizing it smaller.

Input: JPG / PNG / WebP / GIF / BMP · Output: PNG / JPG / WebP.

Features and Limitations

Features

Classic unsharp mask with amount, radius and threshold controls.
Works on each colour channel and leaves transparency untouched.
Live before-and-after preview.
Full-resolution processing on download, all in your browser.

Limitations

Sharpening improves perceived crispness but cannot fix real motion blur or a badly missed focus.
The preview is shown scaled down, so judge fine detail by zooming into the downloaded file.
Too much amount or radius creates bright and dark halos along edges.
Processing happens on your device, so very large files depend on your browser's available memory.

Example

With amount 100% and radius 1.5 px, an edge pixel 20 levels brighter than its blurred surroundings is pushed another 20 levels brighter, which makes the edge look crisper.

Frequently Asked Questions

What are good starting values?

For web-size photos try amount 80–150%, radius 0.8–1.5 px and threshold 2–4. For large prints, a bigger radius of 2–3 px with a lower amount often looks more natural.

Why do I see white outlines around objects?

Those are halos from over-sharpening. Lower the amount or the radius until they disappear.

Can it fix a blurry photo?

It helps a slightly soft picture. A photo blurred by camera shake or wrong focus does not contain the missing detail, so sharpening only adds contrast to the blur.

Should I sharpen before or after resizing?

After. Downscaling softens a picture, so sharpening is usually the last step before saving for the web.