Pixelate Image Online for Free

Choose Find faces. A small face-detection model loads into your browser the first time and marks every face it can see with a box, already covered with the effect you picked. Each box is made a little larger than the face itself, because hair, ears and the outline of the jaw also make a person recognizable.

Then look over the result as if you were the person in it. Automatic detection is a helper, not a guarantee: drag a box over any face it did not mark, and remove a box it put in the wrong place with its × button. In a group shot, it is quicker to fix the few exceptions than to draw every box by hand.

Whether you pixelate or blur a face, strength matters more than the effect you pick. As a rule of thumb, a face should end up no more than five or six blocks wide. At that size there are no features left to read, while a fine mosaic of ten or more blocks across still shows the shape of the face and can be recognized by people who know the person.

Faces are rarely the only giveaway. A school logo, a name badge, a distinctive tattoo or a house number in the background can identify someone just as well, so cover those too before you share a photo of people who did not agree to be online.

Selected areas has two ways to mark what to hide. Box is best for anything rectangular: a license plate, a line of text, a monitor, a window into someone’s home. Drag across it on the image, then move the box or pull its corners until it fits. On a keyboard, arrow keys move the selected box and Shift with the arrows resizes it.

Brush is for shapes a box would overshoot: a tattoo, a pet tag, a reflection, or several people standing behind your subject. Paint over them and the effect follows your strokes exactly. To blur or pixelate the background but keep the subject sharp, paint the background with a large brush. If you would rather swap the background out entirely, remove the background instead.

Boxes, brush strokes and detected faces can be combined in one image, up to 200 areas. Every change can be undone and redone, and Reset returns to the untouched photo.

To make an image pixelated from edge to edge, keep Whole image selected: every part of the picture turns into even square blocks. People use it to hide a spoiler or an explicit image behind a mosaic, to make a deliberately unreadable background for a slide or video, or for the blocky retro look in memes and thumbnails. For a picture that looks badly compressed rather than neatly pixelated, make the image low quality instead.

Pixel size sets how large each block is, in pixels of the original image. Small values keep the picture recognizable with a mosaic texture; large ones leave only patches of color. The blocks always line up in a grid starting at the top-left corner, so the preview on your screen and the downloaded file match block for block.

Pixelating does not change the image size: a 4000 × 3000 photo comes back as 4000 × 3000. To make it smaller for an email or a website, run the result through the image compressor or resize it afterwards.

Text is where pixelation is weakest. When you pixelate text, the letters come from a known font at a known size, and researchers have built tools that rebuild pixelated words by rendering candidate text and comparing the blocks. A light blur leaks even more. For passwords, card and account numbers, phone numbers, addresses and email addresses, choose Black box: it covers the area with solid black and keeps nothing of what was underneath.

License plates are short strings of large characters, so they sit in between. A mosaic with blocks at least half as tall as the characters works on a photo, while a black box is the safer choice for a clear, close-up plate.

For screenshots, save as PNG so the edges of the boxes stay crisp, and check the parts you left visible: notification previews, browser tabs, usernames and profile pictures give away more than people expect. When the private part sits at the edge, cropping it out removes it completely, which is stronger still.

The pixel size and blur strength start at about a fiftieth of the image’s long side, which is around 20 px on a 1000-pixel screenshot and 80 px on a 4000-pixel photo. That default hides a face in a typical portrait; small faces in a crowd shot are hidden even more strongly, because their boxes are only a few blocks wide.

Raise the slider until you can no longer tell what is underneath at the size people will see the image, then go a step further. Blur needs a higher setting than pixelate for the same result, because it keeps soft outlines and color patches in place. One effect applies to every area in the image; to mix them, for example pixelated faces with blacked-out text, download the first pass and open that file again for the second.

The image is opened, edited and saved by your browser. It is not uploaded, stored or seen by anyone else, and there is no account, watermark or daily limit. The face detector runs on your device too: its model file is downloaded once, kept in your browser’s cache, and only ever sends boxes back to the page.

The downloaded file is a fresh image, so camera details and GPS location from the original are not copied into it. Pixelation only changes what you cover, though. It cannot make a photo anonymous on its own: clothing, surroundings and the account it is posted from can still point to a person, and machine-learning research has shown that weakly pixelated faces can sometimes be matched to known photos. Use strong settings, and do not post a picture at all when hiding one face would not be enough.