FreeImage Sharpener
Sharpen an image
A real unsharp mask with radius and threshold, not a one-button guess.
Drop an image here, or .
Free, no sign-up. Runs in your browser; nothing is uploaded.
Image Sharpener: how to use it
- Drop in a slightly soft photo.
- Set the Amount (how strong) and Radius (how wide the edges it sharpens are).
- Raise Threshold if smooth areas such as skin or sky start to look grainy, then download.
Tips
- Look at the preview at full size. Over-sharpening shows up as bright halos along edges.
- Sharpen last, after resizing, because resizing softens an image again.
- Sharpening cannot fix a badly out-of-focus photo. The AI Photo Enhancer may do better on very soft shots.
Image Sharpener: what it does and when to use it
The sharpener is an unsharp mask, the method photo editors have used since the darkroom. It compares the picture with a blurred copy of itself; where they differ is an edge, and those edges are made a little darker on one side and lighter on the other, which the eye reads as sharper. Amount controls how strong that is, Radius how wide the edges it works on, and Threshold how big a difference must be before it counts as an edge.
Small radius values bring out fine texture such as hair, fabric and foliage; larger values add punch to bigger shapes. Raising Threshold protects smooth areas like skin and sky, so they do not turn grainy. Sharpen last, after resizing, because shrinking an image changes how sharp it looks.
Sharpening makes existing edges crisper; it cannot rescue a photo that is badly out of focus or blurred by movement. Too much creates bright halos along edges. For small, soft or noisy photos, the AI Photo Enhancer or Image Upscaler often give a more natural result.
Image Sharpener: frequently asked questions
Is the Image Sharpener free, and do I need to sign up?
Yes, the Image Sharpener is 100% free with no sign-up, no login and no account. The Image Sharpener runs in your browser, so it has no daily limit and no upload, and saves at full size with no watermark. See why it is free.
How do I sharpen a blurry photo?
Start with a small radius and a moderate amount, and zoom in to check edges. Sharpening makes soft edges crisper but cannot fix real motion blur or a badly missed focus. For noisy, low-quality photos, the AI Photo Enhancer usually does better.
Why does my sharpened photo look grainy?
Sharpening also sharpens noise. Raise the threshold so only real edges are sharpened, or reduce noise first with the Noise Reducer.
Should I sharpen before or after resizing?
After. Resizing smaller softens a photo slightly, so a light sharpen at the final size gives the crispest result. Our guide to resizing explains more.