Pixelate / Redact

The Pixelate / Redact tool breaks an image into a coarse mosaic of solid blocks, the familiar effect used to censor faces, hide names and addresses, blur out screenshots, or just give a picture a retro low-resolution look.

Drop in a JPEG, PNG, WebP or GIF and drag the block-size slider to control how chunky the result is — small blocks soften detail gently, while large blocks reduce a whole region to a few flat squares.

Under the hood each block is replaced by the average colour of the pixels it covers, so the mosaic keeps the broad shapes and tones of the original while throwing away the fine detail that makes faces or text legible.

Every change redraws from the untouched source rather than re-pixelating an already-pixelated image, so sliding back and forth never compounds the effect or loses quality.

A note on privacy as redaction: pixelation removes detail but is not a guarantee against determined reconstruction, so for truly sensitive data prefer a solid block — using a large block size here effectively does that.

Critically, the whole process runs in your browser with the Canvas API; the image is never uploaded, which is exactly what you want when the picture contains private information.

When it looks right, download a lossless PNG.