How to pixelate a picture
Upload an image and the Effects tab opens with pixelation already applied. Drag the Pixelate slider between 1 and 40. Higher values make bigger blocks and less detail; at 40 the image is reduced to a coarse grid of colours. Set it back to 0 to turn the effect off.
Block size scales with the image, so the preview and the downloaded file have the same number of blocks across. The effect is applied to the entire image; there is no tool for selecting just one region, such as a face or a licence plate.
Creative uses of pixel art effects
Moderate settings give a retro video-game feel that works for posters, album art and playful profile pictures. Strong settings turn a photo into an abstract colour pattern that can serve as a background or texture. Pixelating a well-known image and asking people to guess it is a popular quiz format.
Try combining it with the Adjust tab: raising saturation makes the blocks punchier, and switching to grayscale gives a newsprint-style mosaic. You can crop to 1:1 first if the result is meant for an avatar.
Pixelation and privacy
Pixelation is widely used to obscure faces or text, but it is not a reliable way to hide information. Small blocks can leave text partly readable, and some patterns can be reconstructed. Because this tool pixelates the whole image rather than a selected area, it is not a redaction tool. If something must not be seen, crop it out of the frame before sharing. The final file is rendered on the server; PNG remains PNG and other formats are saved as JPG.