Blur an image, or part of it

Kinds of blur

Filter › Gaussian Blur is the even softness most people mean by blur: a small radius softens, a large one turns detail into a smooth wash of color. The Filter menu has two more:

• Motion Blur smears along an angle and a distance, as if the subject moved.
• Radial Blur zooms out from a center, or spins around it.

To blur by hand, press R for the Blur & sharpen tool and paint over the parts to soften, with its strength set in the bar above.

Filters are live: each one is a layer you can change at any time. Raise or lower the radius in Properties, hide the filter with its eye in the Layers panel to compare, or paint its mask with the Brush (B), black to take the blur away from a spot and white to add it.

A blurred background behind a person

Phones blur the background in portrait mode; Octoolo can do it afterwards. Select › Background (AI) finds the main subject and selects everything else. The AI part it needs is downloaded once, the first time (about 200 MB), and then runs on your PC with no upload.

• Before adding the blur, choose Select › Modify › Feather… and a few pixels, so the line between sharp and soft is not too hard.
• Add Filter › Gaussian Blur and try a radius of 10 to 30 pixels.
• Look along the edge of the hair and shoulders, and paint the filter's mask where the blur went too far or not far enough.

A real lens blurs more the farther things are, while this blurs the whole background evenly, so keep it moderate for a natural look.

When blur is enough, and when it is not

Blur is fine for faces in the background, a messy room, or a brand you would rather not show. For anything that must stay secret, think twice:

• Text and numbers such as addresses, card numbers, passwords and order codes. Blurred or pixelated text can sometimes be guessed, especially short words in a known font.
• People who must not be recognized, for example in a sensitive story. Select more than the face, and check the result.

For those, cover the area in solid black: select it, press D so the foreground color is black, and press Alt Backspace to fill it. On a screenshot full of private details, a few black boxes are often quicker and safer than blur. Squares are the mosaic look in between; see pixelate image.

Share the export, not the project

The blur stays a separate, live layer while you work, with the sharp picture underneath. That is what makes it adjustable, and it is also why only the exported JPG, PNG or WebP should be shared: in it, the blur is part of the pixels and the sharp version is gone.

A project saved with File › Save, or a copy saved for Photoshop, keeps the layers, sharp picture included. Keep those for yourself. Octoolo does not look for faces on its own; to hide people, select each one, and the blur face page has tips for crowds, children and license plates. Since blurring and exporting happen on your PC, the photo you are protecting is never uploaded to be blurred.