Black Bar vs Blur vs Brush: Choosing the Right Redaction Mode

Redaction looks like a one-button operation: cover the thing, ship the file. In practice the three available modes (black bar, blur, brush) have different strengths and different failure modes. Choosing the wrong one leaks the very information you tried to hide.

The decision tree

Start at the top:

• Is the content recoverable if someone tries hard? Black bar.
• Is the content long-form text where readability is the only concern? Blur.
• Is the content non-rectangular (face, signature, irregular shape)? Brush.

That single question handles 90% of cases. The other 10% needs more thought.

Black bar, the safe default

Black bar replaces the region with solid opaque pixels. There is no information left to recover. It is the right choice for:

• Account numbers, PINs, codes
• Email addresses and phone numbers
• Signatures
• Names that should not appear at all
• Anything you would regret if it were guessable

The downside is purely cosmetic: black rectangles in the middle of a screenshot look obviously redacted, which signals "secret here". If that matters (legal documents, controlled disclosures), accept it. If it does not, black bar is the right call.

Blur, for visual hierarchy, not security

Blur reduces the visual prominence of a region without removing it entirely. The viewer can tell there is text there, that it occupies a certain shape, sometimes how long it is. They cannot read the words. This is fine for:

• Body paragraphs in a long screenshot where the layout matters more than the words
• Background faces in a primary subject photo
• Watermark removal previews (the artistic kind, not the security kind)

It is not fine for:

• Short numeric strings (PINs, codes, last-four digits)
• Short text fields (account names, single-word secrets)
• High-value targets where someone might actually try to recover

The reason: blur is mathematically reversible for high-contrast small content. There are public AI deblurring models, and even without ML, manual character-pattern analysis can guess a 4-digit number from its blurred imprint. The recovery success rate is high enough that security researchers consider blur unsafe for credentials.

For short critical content, always black bar.

Brush, when the shape is wrong for a rectangle

Brush lets you paint over any shape: a face, a signature, a logo, an inked annotation. Use brush when:

• The region is non-rectangular
• You need to redact partial elements (one face in a group photo)
• The redaction edge matters (following a hairline, a signature curve)

The brush in OmegaPix's redactor draws solid pixels, so the redaction is as permanent as black bar. The difference is purely shape.

A practical tip: zoom in (the redactor supports it) before brushing. A redaction that misses the edge of a name by one pixel is a redaction someone can read.

The undo question

Black bar redactions can be undone in the redactor's session history (10 levels) and you can re-place them. Brush strokes are part of the same undo stack. Blur regions are also undoable.

What is not undoable: closing the tab. Once you close, the session is gone. The downloaded file is permanent. Plan accordingly. Verify each redaction before download, not after.

The composite workflow

Most real screenshots need a mix:

1. Black bar over short critical content (PINs, codes, emails)
2. Blur over long content where layout matters but words don't
3. Brush over faces, signatures, irregular shapes

A single image often uses all three. The redactor supports stacking redactions of any mode in a single export.

After redaction

Strip metadata. A screenshot's EXIF often includes the screenshot timestamp, device model, and on iOS even the apps that were open. Run the redacted file through EXIF Remover before sharing it.

The whole workflow stays in your browser. The unredacted original never leaves your device.