How to redact a screenshot on Windows (without leaving the data in the file)

Windows gives you several ways to cover part of a screenshot. They are not equally safe, and the differences are not visible in the result. This walks through each one, says plainly where it fails, and ends with the verification step almost every guide leaves out.

If you only take one thing away: cover it with a solid opaque shape and export a flattened image. Everything below is detail on how to do that in each tool.

Option 1 — Snipping Tool (built in, Windows 11)

Recent Windows 11 builds added redaction to Snipping Tool, including a Quick Redact that uses OCR to find email addresses and phone numbers on its own.

1. Take your screenshot (Win + Shift + S) and open it in Snipping Tool.
2. Choose the redaction tool from the toolbar.
3. Either drag over each sensitive region, or use Quick Redact to let it find contact details automatically.
4. Save as PNG with Ctrl + S. Do not just copy to clipboard and paste into an email client — some clients keep more than you expect.

Where it is strong: it is already installed, it applies a solid block rather than a blur, and the OCR pass catches things you would have missed.

Where to be careful: Quick Redact finds the patterns it knows — emails and phone numbers. It will not find an API key, a licence plate, a face, an account balance or an internal hostname. Treat it as a first pass, then go over the image yourself.

Option 2 — Paint (built in, every Windows)

Crude and completely reliable, which is a reasonable trade.

1. Open the screenshot in Paint.
2. Pick the rectangle shape, set Fill to a solid colour, and set the outline to the same colour.
3. Drag a filled rectangle over each sensitive region.
4. Save as PNG.

There are no layers in Paint. The moment you draw the rectangle, the pixels underneath are overwritten in the working image, and saving writes exactly what you see. The failure mode of “the redaction was a separate object” simply cannot happen here.

Where to be careful: there is no undo once saved over the original, so work on a copy. And do not use the airbrush or the blur-ish effects — only a solid filled shape.

Option 3 — SnapShield AI

This is our tool, so read the following with that in mind. It exists because the two options above are either pattern-limited or manual.

1. Open or paste the screenshot.
2. For automatic detection, run AI Redact — face detection and sensitive-data detection run locally and propose regions for you to accept or adjust.
3. For anything it missed, drag the Redact tool over the region.
4. Export to PNG or JPEG.

Two properties we care about, both of which you should demand of any tool:

• The export destroys the pixels. Redacted regions are replaced in the exported image, and we have pixel-level tests that fail our build if a redacted region still correlates with what was underneath it.
• Nothing is uploaded. Detection runs on your machine. There is no server round trip, which matters because the image you are trying to redact is precisely the image you do not want to transmit.

There is a free tier with no expiry, so you can check both claims yourself before paying for anything.

Option 4 — Things to avoid

The blur or pixelate tool, in any application. Both are reversible; the original characters remain recoverable from the output. This is covered in detail in can blurred text be recovered.

A black rectangle in PowerPoint, Word or a PDF. The shape is an object floating above the content. The text underneath is still selectable and still copies out.

Marking up in a tool and sharing the project file. .psd, .xcf, Figma links and similar keep your redaction as a separate layer over an intact original.

Highlighter pens and semi-transparent shapes. Anything below full opacity leaves a fraction of the original signal, and a levels adjustment amplifies it back into legibility.

The verification step

Do this once and it becomes a habit. It takes about fifteen seconds.

1. Open the exported file — not the editor you made it in — in a different viewer.
2. Zoom to 400% on each redacted region.
3. Raise brightness and contrast to their extremes, and if your viewer has a levels or curves control, drag the black and white points together.

A correct redaction stays a flat, featureless block through all of that. If shapes, edges or ghosting appear, the underlying data survived and the file is not safe to send.

For a stricter check on an image you are about to publish widely, open the PNG in an image editor and inspect the redacted area’s histogram. A truly flat fill has a single spike. Anything with spread means variation, and variation means information.

Do not forget the parts that are not pixels

A screenshot carries more than the picture:

• Metadata. EXIF and PNG text chunks can hold the capture tool, the machine name and timestamps. Strip metadata before publishing anything sensitive.
• The filename. invoice-acme-corp-45000.png defeats the redaction inside it.
• The window chrome. Titles, tab strips, bookmark bars, notification toasts and the taskbar routinely leak account names, internal URLs and who else you were talking to. Crop tightly.
• Reflections and scale. Sidebar counts, scrollbar positions and row totals can reveal the size of a customer list you meant to hide.
• Auto-saved copies. If your editor keeps a crash-recovery file or an undo history on disk, an unredacted version may exist even though your export is clean. Check where your tool writes those, and clear them.

A quick decision table

Situation	Use
One-off, a couple of regions	Paint — a solid filled rectangle
Windows 11, emails and phone numbers	Snipping Tool Quick Redact, then a manual pass
Faces, or many screenshots, or regularly	A dedicated tool with local detection
Legal, medical, or public disclosure	Redact at the source, then capture

That last row is the one people skip. When the consequence of a leak is serious, do not capture the real data and remove it afterwards — put a test account, seeded data, or edited DOM on the screen first, and screenshot that. There is no recovering pixels that were never written.

Related reading

• Can blurred text be recovered? — the maths behind why blur and pixelation fail.
• Redacting screenshots for GDPR — obligations when the data belongs to someone else.