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Blur Image Online

Our free blur image tool softens a photo or hides a face, number plate, or private detail right in your browser. Upload a PNG, JPG, WebP, or GIF, drag the blur slider until the preview looks right, and download the result — no upload to any server, no sign-up, and no watermark.

How it works

A blur softens a picture by spreading each pixel into its neighbours, so sharp edges melt and fine detail disappears. Photographers use a gentle blur to make a background melt away behind a subject, and everyone else uses a stronger blur to hide something that should not be shared: a face in a crowd, a number plate, an address on a parcel, or a name on a document. The strength is measured in pixels — how far each pixel's colour spreads — and the right strength is the lowest one that hides what you need hidden, so the rest of the picture stays as clear as possible.

When you pick a file, the tool first checks that it really is an image: PNG, JPG, WebP, or GIF, judged by the file type your browser reports and the ending on the file name. If you picked a PDF or another file type by mistake, it stops and shows a friendly message instead of a broken download. Then it reads the image and paints it onto a canvas — a drawing surface browsers use for images — at its original size, and the live preview appears with the default 8-pixel blur already applied.

The blur itself uses the canvas blur filter, which spreads every pixel by the radius you choose. The slider runs from 0 pixels, which leaves the picture untouched, to 30 pixels, which turns the whole frame into soft colour with no readable detail. A blur of 2 to 4 pixels gives a gentle softening for backgrounds and portraits. At 8 to 12 pixels small text and number plates disappear, and at 20 pixels or more a face becomes unreadable. The preview redraws as you move the slider, so you can stop at the exact strength where the detail is gone — and the Compare button flips between the original and the blurred version, so you can check before you download.

Blurring never changes the size of the picture: an 800 by 600 photo comes back as 800 by 600, so it still fits wherever the original fit. Quality runs from 0.5 to 1.0 and affects JPG and WebP; PNG is lossless, so the slider is ignored for PNG. If your file is an animated GIF, only the first frame is blurred, because a canvas holds a single still picture — keep the original GIF if you need the movement. The blur is baked into the downloaded pixels, so it cannot be undone; that is what makes it safe for hiding details, and why you should keep your original file.

Not every browser can apply the canvas blur filter, so the tool checks for support before it starts. If your browser cannot do it, you see a clear message explaining the problem and suggesting an update or a different browser, instead of a broken download. The download is named after your original file with blurred added and the ending changed to match the format — street.jpg becomes street-blurred.png — and the page reports the blur strength, the dimensions, and the file size. Because every step happens on your computer, there is no waiting for an upload and no copy of your image sitting on someone else's server.

Worked example

Suppose you photographed a street scene to share online, but a car number plate is clearly readable in the foreground. The photo is street.jpg, 800 by 600 pixels and 210 KB, and you want the plate hidden without ruining the picture.

Step 1: you click "Choose an image" and pick street.jpg. The tool confirms it is a JPG and shows "800 × 600 px, 210 KB" under the file picker, and the live preview appears with the default 8-pixel blur.
Step 2: the plate is already unreadable at 8 pixels, so you leave the slider there — the preview note reads "Blur 8 px (medium), 800 × 600 px". You press Compare to check the original, and the plate is sharp there, which confirms the blur is doing its job.
Step 3: you leave the output on PNG and click "Download blurred image". The result is street-blurred.png, still 800 by 600 pixels, with the whole scene softly blurred at 8 pixels and the plate gone for good.

If you had only wanted a gentle background softening, 3 pixels would have kept the buildings recognisable while taking the hard edge off the picture. And if a face in the crowd needed hiding instead of a plate, 20 pixels or more would be the safer choice — at that strength no face can be recognised, though the rest of the scene turns into soft colour too.

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