Pixelate
Mosaic / blocky pixels — useful for redaction too.
This runs in your browser. Nothing is uploaded.
About Pixelate
Replaces square blocks of pixels with their average colour at a block size from 2 to 40 pixels, computed in your browser — the familiar mosaic used to hide faces and screenshots.
Most pixelation is redaction. A screenshot with an email address in the corner, a street photo with someone else's child in the background, an invoice with an account number on the third line. The rest is aesthetic: mosaic effects, deliberate low-resolution game art, the censor-bar look. Both uses want exactly the same operation, which is why a single block-size slider covers them.
The Block slider sets a size in pixels. Your image is scaled down so that each block collapses to one pixel, with smoothing enabled so that pixel is a genuine average of everything beneath it, then scaled back up to the original dimensions with smoothing switched off — which paints each average as a hard-edged square. Two pixels is the enforced floor, so dragging the slider to 1 still gives you 2.
Pixelation obscures; it does not encrypt. Every block still carries the average colour of what sat under it, and for text rendered in a known font at a known size that leak has proved sufficient — researchers have recovered pixelated text by rendering candidate strings and matching block averages against the mosaic. Faces and photographic content are far harder to attack. Still, when the content would cause real harm if read, crop it out instead.
How to use Pixelate
- 1Drop your image onto the panel, or click to browse.
- 2Set Block. Bigger blocks destroy more; 12 to 20 is typical for hiding text in a normal screenshot.
- 3Click Apply preview and check that nothing readable survived.
- 4Click Download to save the PNG.
What it won't do
- Whole-image only. Use the redact tool to mosaic a single rectangle.
- A block size of 2 is the minimum, so even the lightest setting visibly softens fine detail.
- Not a security guarantee — mosaicked text has been reconstructed before.
Common questions
Can pixelated text be recovered?
Sometimes, yes. Because each block holds the average colour of the text under it, an attacker who knows the font and size can render guesses, pixelate them the same way, and compare. This has been demonstrated on real redactions. Larger blocks make it much harder, but the only certain fix is removing the region rather than mosaicking it.
How do I pixelate only one part of an image?
Use the redact tool instead. This page applies the mosaic to the entire image, whereas redact takes X, Y, width and height sliders and pixelates only that rectangle, leaving the rest untouched. That is the right tool for a face in a group photo or one line on a document.
What block size hides a face properly?
As a rule of thumb, the block needs to be large enough that a face spans no more than about five or six blocks across. On a face that is 200 pixels wide, that means a block of 30 to 40. Anything finer leaves recognisable structure in the eyes and mouth.
Does pixelating also remove the photo's metadata?
Yes, as a side effect. The download is drawn out of a canvas, so it contains the pixels you can see and nothing else — no EXIF, no GPS coordinates, no camera model. If you want that guaranteed for a file you have not pixelated, use the EXIF stripper.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation