How to Properly Redact Sensitive Info from Images

Privacy & Self-Hosting January 22, 2026

Black boxes are not enough if you skip the metadata

You have got a screenshot with sensitive data. Maybe it is a support ticket, a config file, or something you need to share but can not show everything. So you draw a black box over it and call it done.

Not so fast. That black box might not be as solid as you think. And even if it is, the image itself can still leak info through metadata.

Here is how to do it right.

Redacting with MS Paint (Windows)

MS Paint is free, simple, and gets the job done. Here is the process:

Use Snipping Tool to create a screenshot
Copy or open the screenshot in MS Paint
Select Fill in the toolbar and set it to solid color
Select a color for Color 1 and Color 2 (black works, or pick an agreed-upon color)
Select the Square/Rectangle tool
Use the magnifier in the bottom right corner to make it easier to see all text
Draw a rectangle over each piece of text that needs to be redacted (repeat for each piece)
Save as JPG to remove any layering. Do not save as PNG.

Why JPG?

JPG compression flattens and reprocesses the image data. Some advanced editors (Photoshop, Fireworks) can save PNG files with hidden layers that could be recovered. JPG eliminates that risk entirely and also strips out any potential compression artifacts from the original.

Do Not Forget the Metadata

Here is what most people miss: images contain hidden data called metadata. This can include:

Date and time the image was taken
Device info (camera, phone model)
GPS coordinates (if location was enabled)
Software used to edit the image
Sometimes even thumbnails of the original image

AI tools can pull metadata from images to potentially recover redacted info or identify the source. If you are sharing something sensitive, strip the metadata too.

Removing Metadata on Windows (Built-in)

Right-click the image file and select Properties
Go to the Details tab
Click Remove Properties and Personal Information
Select "Create a copy with all possible properties removed" or choose specific fields
Click OK to create a clean file

That is it. No extra software needed.

Removing Metadata on Mac

Mac does not have a one-click option like Windows, but here are your choices:

Screenshot Method (Quick but lossy)

Take a screenshot of the image. This strips metadata but reduces quality.

Preview Export Method

Open the image in Preview
Export as PDF
Convert back to JPEG
Metadata is removed in the process

Third-Party Tools

ExifTool - Command-line, powerful, free
MetaImage - GUI app for Mac

Removing Metadata on Linux

Linux users can use ExifTool from the command line:

# View metadata
exiftool image.jpg

# Remove all metadata
exiftool -all= image.jpg

Simple and effective.

TL;DR

Use solid rectangles to redact text in MS Paint (or similar)
Save as JPG, not PNG, to flatten layers
Remove metadata before sharing. Windows has this built-in. Mac and Linux need extra steps.
Metadata can leak info like location, device, and timestamps
AI can sometimes recover redacted info from metadata or improperly flattened images