What pixelating does to a picture
Pixelating cuts a picture into squares and fills each one with a single colour, the average of what was there. The larger the squares, the less is left to see. The Strength slider sets their size. It is measured against the picture, so the same setting looks the same on a small file and on a large one.
| You want to | Choose | Good to know |
|---|---|---|
| Hide a face or a number plate | Selected areas | Squares large enough that nothing can be guessed |
| Hide a line of text or a number | Selected areas, a high strength | Small squares over text can be decoded |
| Give a whole picture the mosaic look | Whole image | A low strength keeps the subject recognisable |
Pixelate or blur?
Both remove detail, and the tool does both: the Effect buttons switch between them. Pixelate is the look of hidden faces on television: it shows at once that something was covered on purpose. Blur is softer and suits backgrounds, where the change should not draw the eye. For privacy the strength matters more than the effect.
Can a pixelated picture be un-pixelated?
Not from the file: each square holds one colour, and the detail that was there is gone. But what is left can still give things away. A face under small squares stays recognisable to people who know it, and text under small squares can be worked out by software that tries letters until the squares match. Use squares large enough that nothing can be guessed at full size. For a password, a card number or an ID, crop the area out of the picture instead.
How to pixelate a face in a photo
Choose Selected areas and drag on the picture to draw an area over the face. Oval follows a face more closely than a rectangle. Add an area for every face you want to hide. Soft edges blend the squares into the picture; switch them off for a block with hard edges.
What happens to the size and the quality
The picture keeps its width and height, and its format unless you pick another. A PNG is saved without loss. A JPG or a WebP is compressed again, at high quality. Data stored inside the file, such as the place and the camera, is not carried over. Only a very large picture changes size: one longer than 4096 px on a side is scaled down to that, and the tool tells you so.