How to censor a screenshot on a Mac
You are about to post a screenshot and there is a face, a name, or a message in it that should not go out. macOS has no dedicated censor button, so the built-in way is to cover the area with a solid shape in Preview and export a fresh file. That is genuinely fine for a casual share, with one catch worth knowing: a blur or a pixelate looks like a censor but can be undone, so for anything that actually matters you want a cover that removes the pixels rather than smears them.
The quick way, in Preview
For a face in a meme, a username in a review, or a name in a group chat, Preview is all you need and it is already on your Mac.
- Open the screenshot in Preview.
- Click the Markup button (the pen tip) to show the Markup toolbar.
- Choose the rectangle from the Shapes menu. Preview has no blur or pixelate tool, so a shape is the tool.
- Set the fill to solid black (or any solid color) at full opacity and draw it over what you want to hide.
- Export a new file with File then Export, rather than saving over the original. This flattens the cover into the image.
The Photos app can do a rough job too: its Retouch tool smudges an area rather than covering it, which can work for a small blemish but is imprecise and was never built to hide text. For a clean censor, the solid cover is more reliable.
Which censor methods actually hold up
Not every way of hiding something is equal. Here is how the common methods hold up if someone later tries to recover what was under them.
| Method | Holds up? | Why |
|---|---|---|
| Solid box, flattened | Yes | The pixels underneath are painted over and nothing sits on a removable layer once you export a fresh file. |
| Blur or pixelate | Not for text | Each block still depends on what was beneath it, so short, structured text can be rebuilt (Depix, Unredacter). |
| Photos Retouch smudge | Roughly | Imprecise and content-dependent. Fine for a smudge, not for a name or a number you need gone. |
| Box on a separate layer | No | If you never flatten it, the cover can be deleted or the text selected straight out from under it. |
| Content-independent scrub | Yes | The region is rewritten with a pattern unrelated to the original, so there is nothing left to solve for. |
If you are only covering a face or a background, a blur reads better than a hard black box and is usually safe enough. The moment you are covering words, digits, or a small logo, switch to a solid cover or a scrub. More on why in whether a blurred image can be reversed and the difference between obfuscation and redaction. For faces specifically, see how to blur a face in a photo on a Mac, and for covering any region there is how to blur part of a screenshot on a Mac.
Censoring a screenshot the fast way
The manual route works, but covering something, flattening it, and checking the export every time is fiddly, which is why I built ScrubShot. Press Fn + Space, it grabs the screen and opens an editor, and you drag over whatever should be gone. The Scrub tool rewrites that region with a content-independent mosaic: each block is filled from pixels sampled at random across the selection, so the cover has no relationship to the text or face that sat there, and it is baked straight into the image. It looks like a censor and reverses to nothing by design.
From there you can crop, add a marker or a label, then Copy or Save. The whole capture-and-scrub flow runs on your Mac and makes no network connections, so a screenshot you are censoring never leaves the machine. For the full walk-through of doing this properly, see how to redact a screenshot on a Mac.
FAQ
- How do you censor a screenshot on a Mac?
- Open it in Preview, click the Markup button, choose the rectangle shape and set its fill to solid black at full opacity, then cover the part you want gone and export a fresh file with File then Export. That last step matters: it flattens the box into the image so nothing sits on a separate layer. macOS has no dedicated censor or blur tool, so a solid cover you flatten is the safe manual route.
- Does macOS have a blur or censor tool built in?
- No. Neither Preview's Markup nor the Screenshot editor that pops up after you grab a shot has a blur or pixelate option. What they do have is shapes, so the built-in way to censor something is to cover it with an opaque rectangle, not to blur it. For an actual blur you would need a third-party app, and for anything sensitive a blur is the wrong choice anyway.
- Is blurring or pixelating enough to censor something private?
- For a face in a crowd or a background, a heavy blur is usually fine. For text, a number, or a small logo, it is not: pixelated text can be reconstructed character by character, which is exactly what Depix and Bishop Fox's Unredacter demonstrate. If what you are covering would matter in the wrong hands, cover it with a solid block or scrub it, do not blur it.
- How do I censor part of an image without leaving a trace?
- Replace the pixels rather than sitting something on top of them. A solid fill flattened into a new file works, and so does a tool that rewrites the region. Then check the export: zoom in, push brightness and contrast to their extremes, and try to select text over the censored area. If nothing shows and nothing selects, it is gone.
Try it
ScrubShot is a one-time $25 purchase with a seven-day free trial, no account and no card up front. It runs entirely on your Mac.
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