Add blur to a photo

This mode blurs the entire photograph evenly. It opens with a Gaussian blur already applied, so the first thing you see is a result rather than a menu, and the amount is one slider you can drag, scrub or type into. Under it, the radius that amount produces is printed in the picture’s own pixels — the same number the saved file is made with, not a rescaled preview figure.

A blurred background for a slide, a soft wallpaper, a picture you want to show without showing: the jobs differ, the control is the same.

• Gaussian — the lens-like default; soft and even.
• Box — flatter, with a slightly squared look.
• Motion — a streak in one direction; set it with the dial.
• Zoom — a burst outward from a centre you drag on the picture.
• Pixelate — square blocks; the readout gives the block size and how many fit across.

To keep a person sharp and soften only what is behind them, use blur the background. To soften one area, use blur part of an image. For square blocks with the block size as the main control, use pixelate an image.

• A blur is an effect, not a covering: what was there is spread out, not removed.
• Saving as JPG fills anything transparent with white; PNG and WebP keep transparency.
• An animated GIF or WebP is saved as its first frame.
• JPG, PNG, WebP, GIF, BMP and ICO open here. HEIC and TIFF open only where the browser itself reads them.

How strong is the blur, in pixels?

The line under the Amount slider prints it: the Gaussian or box radius, the motion streak length, or the pixelation block size, in the picture's own pixels at full resolution. You can type an amount instead of dragging, and the readout follows.

What is the difference between Gaussian and box?

A Gaussian weights nearby pixels more than distant ones, which is what an out-of-focus lens does, so it looks natural. A box blur weights every pixel in its square equally, which looks flatter and slightly blocky. Motion smears along one direction you set with the dial; zoom smears outward from a centre you drag.

Will the saved picture be smaller than the original?

No. The preview runs on a lighter copy, but saving runs the blur on the full-resolution picture, scaled so the result looks the same, and writes it at the original's width and height.

Can I blur the whole photo and still keep one thing sharp?

Yes: switch to Background to keep a subject sharp, or Focus for a tilt-shift band or a sharp ring. Or keep the whole-photo blur and draw a region in Regions with Invert on.

Is blurring the whole photo enough to hide what is in it?

Not dependably. A blur spreads what was there rather than removing it, and large shapes, colours and faces you know stay recognisable. To hide something, cover it with a solid fill in the Privacy mode.