Free Online Unsharp Mask Tool — Professional Image Sharpening
Easily sharpen your images with professional-grade unsharp mask technology — the same technique used by photographers and designers in Photoshop and other professional editing software. Unlike simple sharpen filters, unsharp mask gives you independent control over the Amount (how much sharpening to apply) and Radius (how wide the edge enhancement extends), allowing for precise, artifact-free results. Ideal for correcting soft focus, enhancing texture details, and preparing images for print. All processing happens in your browser for complete privacy — your images never leave your device.
Upload the image you want to sharpen by dragging it onto the upload area or clicking to browse your files.
Adjust the Amount slider to control sharpening intensity, and the Radius slider to control how far from edges the effect extends. Lower radius for fine details, higher radius for broader edge enhancement.
Download your sharpened image in its original format when you're satisfied with the result.
Tips for Using Unsharp Mask
- For portrait photos, use a small radius (1-2px) with moderate amount (50-80%) to enhance eyes and hair without making skin texture look harsh.
- For landscape and architectural photos, try a medium radius (3-10px) with higher amount (100-200%) for dramatic edge definition that makes details pop.
- The classic unsharp mask technique: start with a medium radius (3px) and moderate amount (80%), then fine-tune. If halos appear around edges, reduce the amount before reducing the radius.
Frequently Asked Questions — Unsharp Mask
Is the unsharp mask tool really free?
Yes, completely free. No registration, no hidden charges, no watermarks, and no file size limits. All processing happens locally in your browser — your images never leave your device.
How does unsharp masking work?
Unsharp masking works in three steps: 1) Create a blurred copy of the original image using a Gaussian blur (controlled by the Radius parameter). 2) Subtract the blurred version from the original to isolate the high-frequency detail layer — this is the 'mask' containing edges and textures. 3) Multiply this mask by the Amount value and add it back to the original. The result: edges are enhanced while smooth areas remain untouched.
What is the difference between Amount and Radius?
Amount (0-500%) controls how much sharpening is applied — higher values produce more dramatic edge enhancement. Radius (0-100px) controls the width of the edge enhancement effect — a small radius (1-3px) sharpens fine details like skin texture, while a large radius (20-100px) enhances broader edges like object outlines. Think of Amount as 'how strong' and Radius as 'how wide'. At maximum settings (500% / 100px), the effect is very dramatic — dial in gradually.
What image formats are supported?
JPG, PNG, WebP, BMP, AVIF, GIF, TIFF, SVG, HEIC and more. The sharpened result is saved in your original upload format, preserving compatibility.
How is unsharp mask different from regular sharpen?
A regular sharpen filter (like our standalone Sharpen tool) uses a fixed convolution kernel with a single intensity control. Unsharp mask gives you independent control over Amount and Radius, allowing more precise tuning. Regular sharpen applies a fixed-width edge enhancement, while unsharp mask lets you choose between fine detail sharpening (small radius) or broad edge enhancement (large radius) — making it more versatile for different types of images.
Can unsharp masking fix blurry photos?
Unsharp mask can improve the appearance of slightly soft images by enhancing edge contrast, but it cannot fully restore severely blurred or out-of-focus photos. It works best as an enhancement tool for images that are already reasonably sharp. For more significant blur correction, try our dedicated Deblur tool, which uses a more aggressive unsharp mask tuned for blur restoration.
How large of an image can I process?
Our tool handles images up to 50 megapixels (50,000,000 pixels total). If your image exceeds this limit, you'll see a warning and can try a smaller version before applying unsharp mask.