Blur vs black box for redaction
Three mask styles, three trade-offs. Here's when to use each, and when one will get you in trouble.
Black box
A solid rectangle of colour rendered into the image. Once exported, the pixels under the mask are gone for good.
Use for: credit card numbers, passwords, social security numbers, government IDs, anything that must be unrecoverable.
Watch out for: matching the box colour to the surrounding background and accidentally hiding the mask itself. Use a contrasting colour so reviewers can see the redaction.
Pixelate
The mask area is downsampled so individual characters dissolve into a few large blocks.
Use for: faces in social shots, screenshots where you want context to remain visible, casual blur over avatars.
Watch out for: pixelating large text. A long string of digits with too few pixel blocks per character can sometimes be partially reversed by averaging.
Blur
A Gaussian blur is applied to the area. Soft, visually pleasant.
Use for: background context, low-risk text, decorative content.
Watch out for: treating blur as security. Blurred text — especially big, high-contrast text — can sometimes be deblurred, OCR'd, or read at a glance by a careful viewer.
Quick rules
- If the data is sensitive, use black box.
- If the aesthetics matter and the data is low-risk, blur or pixelate.
- For faces specifically, pixelate is a good compromise: hides identity, keeps the photo natural.
Reversibility, in plain terms
Modern image processing can recover surprising amounts from a light blur. Pixelate is harder to reverse but not impossible. Black box is the only mask that is guaranteed unrecoverable, because the original pixels are replaced before export.
Try them side by side
Open Redacted, draw the same selection three times with three different mask styles, and compare. The right choice depends on what you're hiding and who is looking.
FAQ
Can I mix mask styles in one image?
Yes. Each selection has its own mask style.
Which is fastest?
All three render instantly in Redacted. Performance is not a meaningful trade-off.
What about emoji masks?
The emoji mask covers the area with a sticker. It's playful — fine for social, not for serious redaction.