How blurring works
Blurring averages each pixel with its neighbours. The more neighbours included, the softer the result. The size of that neighbourhood is called the radius, measured here in pixels. A radius of 1 or 2 takes the edge off fine detail, while a radius near the top of the scale turns a picture into a smear of color where only broad shapes remain.
This tool applies the blur to the entire image. There is no brush or selection area, so you cannot blur just a face or a license plate and leave the rest sharp. The effect uses your browser's canvas filter, so it is processed on your device and the picture is not uploaded.
The radius is a number in pixels, so the same setting looks stronger on a small image than on a very large one. A 10 pixel radius on a thumbnail is dramatic, while on a very high-resolution photo it is subtle.
When blurring an image is useful
A softened picture makes a good background behind text, since less detail means less competition with the words on top. It can also suggest depth, give a sense of motion, or tone down a busy photo in a layout.
It is sometimes used to hide information. Be careful here: a light blur can still be readable, and a determined viewer may recover more than you expect from text blurred only a little. For genuinely sensitive content, a heavy blur is the minimum, and covering the area completely in an editor is safer. Since this tool blurs the entire image, it is not designed for hiding part of a picture.
Blur is also a quick way to create a placeholder or preview version of an image.
How to blur an image with this tool
- Drag an image onto the drop area, or click to choose a file.
- You see the Original with its file name, size and dimensions.
- Move the Blur radius slider. It runs from 0 to 30 pixels in steps of 1 and starts at 4.
- Click Blur. The softened picture appears under Result, with a size comparison.
- Not right? Change the slider and click Blur again. Each run starts again from your original image.
- Click Download. The file is named after your original with -blur added, and it is saved as a PNG.
Use Start over to pick a different image.
Tips and limits
The output is always PNG, whatever the input was. PNG is lossless, so a blurred photo can be larger in file size than the original JPG, even though it holds less detail. If size matters, run the result through Image Compressor.
Blurring cannot be reversed in any reliable way, so keep your original. A radius of 0 leaves the picture visually unchanged.
The blur depends on your browser's support for canvas filters. If you click Blur and the result looks identical to the original at a high radius, try a different or newer browser.
Edges of the picture may look slightly different from the center, since there are fewer neighbours to average there. To bring detail back in a soft photo, Sharpen Image does the opposite, though it cannot recover detail that is gone.