Image Redaction Tool
Redact regions of an image with a solid block, so the hidden pixels are genuinely destroyed rather than covered, with an explanation of why blurring and pixelation are not redaction.
Last reviewed by the Radiatus Cloud team
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Blurring is not redaction
A blurred or pixelated region still contains the original information in reduced form, and that information can frequently be recovered. Pixelation in particular is reversible when the hidden content is drawn from a small set of possibilities: text in a known font, a number plate, a date. An attacker can render every candidate, apply the same pixelation, and compare, which recovers the original in seconds. Published cases have recovered credit card numbers and names from pixelated screenshots by exactly this method.
Solid blocks destroy the pixels
Painting a solid rectangle over a region and re-encoding the image replaces those pixels entirely. There is nothing left to recover, because the information is gone rather than transformed. This is the only treatment that is genuinely irreversible, and it is why redacted documents use black boxes rather than blurring.
The other ways redaction fails
A shape drawn on top in a PDF or a design file hides nothing, since the content beneath is still in the file and moving the shape reveals it. Cropping a screenshot in some phone galleries has historically left the original data in the file. And metadata survives everything done to the pixels: location, device and timestamps sit in a separate part of the file and need removing separately. This tool re-encodes the image from a canvas, which discards the original metadata along with the redacted pixels.
Related tools
- EXIF Viewer — Extract hidden EXIF data (Camera, GPS, Settings) from images.
- Favicon Generator — Generate favicons and app icons at every required size from one source image, with the exact HTML to reference them.
- Placeholder Image Generator — Generate placeholder images at any size with custom colours and label text. Produced in your browser as downloadable files, no external hotlinking.
- Image Resizer — Resize images in your browser with aspect ratio control and format conversion. Files are processed locally and never uploaded.
Frequently Asked Questions
Why is pixelation not safe?
Because the original content can be recovered when it comes from a small set of possibilities, such as text in a known font or a number plate. An attacker renders every candidate, applies the same pixelation and compares. Credit card numbers and names have been recovered from pixelated screenshots this way.
Is blurring any better?
Not reliably. A blur is a reversible transformation in principle, and strong deblurring of a known blur radius recovers a great deal. Neither blur nor pixelation removes the information; only replacing the pixels does.
Does covering something in a design tool work?
No. A shape placed over content in a PDF or a layered file hides it visually while the content remains in the file, and moving or deleting the shape reveals it. The content must be removed, not covered.
What about metadata?
It survives anything done to the pixels, since location, device and timestamps sit in a separate part of the file. This tool re-encodes from a canvas, which discards the original metadata as a side effect of how it works.
Can I recover an image after redacting it here?
No, and neither can anyone else. The redacted pixels are overwritten in the canvas before the file is produced, so the output genuinely does not contain them. Keep your own copy of the original if you need it.
Privacy & Security
Everything runs in your browser; nothing is uploaded.
How to Use
Upload an image, drag over the regions to hide, and download the redacted copy.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
EXIF Viewer
ImageExtract hidden EXIF data (Camera, GPS, Settings) from images.
Favicon Generator
ImageGenerate favicons and app icons at every required size from one source image, with the exact HTML to reference them.
Placeholder Image Generator
ImageGenerate placeholder images at any size with custom colours and label text. Produced in your browser as downloadable files, no external hotlinking.