Blur Image
Blur an entire image by an adjustable radius, with the original and the result shown side by side. Three box passes are used rather than one, which approximates a true Gaussian blur closely enough that no banding or boxiness shows in the result while staying fast enough to update as you drag the slider. Transparency is handled correctly: the alpha channel is premultiplied before blurring, so a transparent PNG does not develop the dark halo around its edges that a naive blur produces. To blur only part of an image — a face or a number plate — use the censor tool instead, which blurs a region you draw.
How far each pixel is averaged with its neighbours. Three passes are used, which approximates a Gaussian blur closely enough that no banding shows.
Frequently asked questions
How do I blur an image?
Upload it, drag the blur radius slider, and download the result. The preview updates as you drag so you can judge the strength directly.
How do I blur only part of a photo?
Use the censor tool instead — it lets you draw a region over a face, a number plate or an address and blur or pixelate just that area.
Is this a Gaussian blur?
It is three box-blur passes, which is a very close approximation to a Gaussian and much faster. The difference is not visible in a photograph.
Will a transparent PNG blur correctly?
Yes. Alpha is premultiplied before the blur runs, which prevents the dark fringe that appears when transparent pixels are averaged as if they were black.
Does blurring reduce the image quality?
Blurring deliberately removes detail and cannot be undone, so keep your original. The file itself is re-encoded at the format and quality you choose.
Is the photo uploaded anywhere?
No — the blur runs on your device, and the image is never sent to a server.
Related tools
Censor Image — Blur or Block Out a Region
Drag over faces, names or licence plates to blur, pixelate or black them out, then download the censored image.
Pixelate Image
Apply a mosaic effect to a whole image, with a block size slider — processed entirely in your browser.
Brightness & Contrast Editor
Adjust brightness, contrast, saturation, hue and sepia with presets and a live comparison.