Blur Image Online – Blur a Whole Photo or Just a Face, Free

Before a photo goes public, the private details have to go: a child’s face, a licence plate, a name on a document, a screen in the background. This free blur tool works two ways. With no areas drawn, it blurs the whole picture — handy for backgrounds. Or drag a rectangle or ellipse over exactly what must be hidden, and only that area blurs while the rest of the photo stays sharp.

The blur strength is one slider, the preview is live at full resolution, and the processing happens in your browser: the unblurred photo never leaves your device.

How to blur part of an image

Click the file box and choose your image.
Set the blur strength. For hiding things, stronger is safer — start at 25 px or more.
Pick Rectangle or Ellipse, then drag on the photo around the face, plate or text you want to hide. Draw as many areas as you need; Undo and Clear fix mistakes.
Click Download blurred PNG. The guide outlines are not in the download.

Want the whole picture blurred instead — for a website background, say? Skip step 3 entirely: with no areas drawn, the full image is blurred.

A worked example, with the numbers

A 2400 × 1600 street photo with a plate you can read. At a blur strength of 30 px, the blur kernel is about the height of the plate’s characters, so the letters dissolve into colour — no software can reconstruct them. A face needs roughly the same treatment: once the blur radius approaches the distance between the eyes divided by two, recognition software and human eyes both fail. The rest of the photo — the car, the street, the light — stays pixel-sharp.

Blur, pixelate or black out?

Blur looks natural and keeps the photo’s feel. Right for faces in family photos you still want to enjoy.
Pixelation (our image pixelator) has a mosaic style and destroys detail in hard blocks — a good choice for documents and screens.
A solid black box, drawn in any editor, is the most brutal and the safest for the most sensitive data — passwords, account numbers.

Whichever you choose: weak settings can be partially reversed by sharpening algorithms. For anything genuinely sensitive, overdo the strength.

Honest limitations

Areas are rectangles and ellipses — no freehand shapes or face detection. The blur is baked into the downloaded PNG, so keep your original somewhere private; it cannot be recovered from the blurred copy, which is the point. On very old phones a full-res photo can take a moment to re-blur when the slider moves.

A five-second checklist before you post

Zoom to 100% on every blurred area and try to read or recognise what is under it. If you can, your audience can.
Check reflections — windows, mirrors, glossy screens, even cutlery can mirror a face or a document.
Check the edges of the frame: house numbers, badges, sticky notes and second screens live there.
Re-save, do not layer: post the blurred PNG itself, never a file that still contains the original underneath.

Frequently asked questions

Can a blurred face be unblurred?

Not meaningfully, at strong settings. Light blurs can be sharpened a little, which is why this tool goes up to 60 px and why the guide above says: for real secrets, be generous.

Does the tool upload my photo for processing?

No — and for a privacy tool that matters doubly. The original and the blurred copy both live only in your browser tab.

Why does the edge of my blur area look soft?

The blurred copy is padded before blurring precisely so areas do not show a sharp echo of hidden content at their borders. The soft seam is the safe behaviour.

Embed this tool on your website — free

Copy the code below to add this working tool to your own page. A small credit link stays with it — that’s all we ask.