UtilForge
Free · runs on this device

Redaction checker: is it really blacked out?

100% freeNo sign-upsNo trackingKeeps working with the internet off

This redaction checker tells you whether the words under a black box can still be read. Choose a PDF (Portable Document Format) file that someone has blacked out. This tool checks whether the words underneath can still be read, and looks for a few other common leaks. It only reads the file and never changes it. The file stays on your device.

The short answer. Often not. A black box drawn over text hides the words from sight but can leave them in the file, where anyone can copy them out. This tool checks a PDF file for exactly that.

How it works, in four steps

  1. Paste or chooseChoose a blacked-out PDF (Portable Document Format) file.
  2. The check runs on your own phone or computerWhat you add stays on your device, and the page keeps working with the internet off.
  3. Read what it found and what to do nextSee whether the words under each black box can still be read, and what to do about it.
  4. What this check cannot doIt does not fix the file, and it cannot open encrypted or password-protected PDF files.

Check a PDF file

Test that it stays on this device

  1. Load this page.
  2. Turn off your wifi, or switch on airplane mode.
  3. Choose a PDF file. The check still runs.

What this tool is not

  • It does not make anybody follow any law, and it does not certify anything.
  • It is not a redaction tool (a tool that blacks out text for you). It does not remove, fix or clean anything, and it does not save a changed PDF file.
  • It is not a guarantee. A clear result means these checks found nothing. It does not mean the file is safe.
  • It is not a way to hide anything from courts, regulators or law enforcement.

What it cannot check

  • Encrypted or password-protected PDF files are not opened.
  • Very large files may use up all the memory in the browser tab.
  • These checks do not detect everything. A clear result is not a guarantee.
  • Even when text has been removed properly, the width of the removed area stays visible, and that can hint at how long the text was. This tool does not check for that.
  • Some scripts that are not written in Latin letters may be read imperfectly.
  • This tool does not fix anything. It only tells you what it found.

This tool checks PDF files. Release Check also checks Word, Excel and PowerPoint files (including ones exported from Apple or Google apps) for hidden sheets, tracked changes and comments. It is free to try.

Questions people ask

Who made this?

UtilForge makes it. UtilForge is a website of free cybersecurity tools. The About page explains why the tools were made, and the Contact page is the way to reach us.

Is this a scam site?

You do not have to take our word for it, because you can check. This page does not ask for payment, a sign-in or card details. It is set so that your browser stops the page sending anything off your phone or computer, and you can test that: let the page finish loading, switch the internet off, then use it. It keeps working, because it has nowhere to send anything. If you are still unsure about any website, do not type anything private into it. UtilForge also sells optional packs of tools through Gumroad, and nothing on this page needs one.

What happens when I close the page?

The file you opened is gone from the page. It was only ever read on your device, and the page never changes it. It saves nothing in your browser and puts nothing in the web address of the page. If you chose to download the text report, that file stays in your downloads folder until you delete it.

Does it cost anything, and do I need to sign in?

It is free, and you can start straight away. UtilForge also sells optional packs of tools through Gumroad, and nothing on this page needs one.

How can I tell whether a blacked-out PDF file still shows what is underneath?

Drop in a PDF file that someone has blacked out. It checks whether the text underneath can still be recovered, and looks for a few other common leaks. It only reads, and it never changes your file.

Does a clean result mean the file is safe?

No. A clean result means these checks found nothing, not that the file is safe. The checks do not detect everything.

Can it fix the PDF file?

No. It does not remove, fix, clean or export a modified PDF file. Redaction Studio is the tool that removes the content.

What can it not check?

It does not open encrypted or password-protected PDF files. Very large files may exhaust the browser tab's memory. Even perfectly removed text leaves the width of the removed area visible, which can hint at length, and it does not check for that. Some non-Latin scripts may extract imperfectly.

Does it check Word, Excel or PowerPoint files?

No, it checks PDF files. Release Check also checks Word, Excel and PowerPoint files (including ones exported from Apple or Google apps) for hidden sheets, tracked changes and comments, and it is free to try.

Did this check help you?

Tell UtilForge what worked and what did not. Each button opens an email to lindsay@utilforge.org that you write and send yourself. UtilForge will only quote your words on this site if you say it may, and then with your first name and country only.

Yes, it helpedSomething was missing

The whole method in one book. “How to Become Safer Online” is a free large-print guide to the five steps most scams follow, and what to do if money or details have already gone. Read or print the free book.