Is the text still there?

A black box drawn over words in a PDF (Portable Document Format) file can leave the words in the file, and anyone can copy them out. To test a redacted PDF file, open the file you are about to send, select the text under the boxes, copy it into a blank note and search the file for a word you covered.

The short answer. A black box can sit over text that is still in the file. Open the file you will send, select all and paste into a blank note, search for a covered word, and if the text appears use a tool that removes it.

Last reviewed 4 October 2026. Based on Adobe’s help pages, a United States National Security Agency (NSA) guide reported by the Federation of American Scientists, and UtilForge’s own checks.

Why a black box is not always a redaction

A PDF file is made of layers. A black rectangle added on top of a paragraph is one layer, and the paragraph is another, so the text can still be in the file. Adobe’s help describes a dedicated Redact tool in Acrobat Pro for permanently removing content, and a separate Sanitize function for hidden information. The NSA guide “Redacting with Confidence” (issued December 2005, reported on 20 January 2006) says that merely converting a Word document to PDF file does not automatically remove all of its metadata, the hidden details stored inside a file.

A test you can do yourself

Run this on the exact file you plan to send, not on the original.

1. Select and copy. Open the PDF file, press Select all (Ctrl+A, or Cmd+A on a Mac), then copy. Paste into a blank note or text file. If words you covered appear, the text is still in the file.
2. Search. Use the PDF file viewer’s search for a name or number you covered. If the viewer finds it, the text is still there.
3. Check the file’s details. Open the document properties and look at the author, title and dates. These can name a person or an organisation.
4. Try another viewer. Open the file in a second program, because two programs can show different things.

A page that is a scan of paper holds a picture, so the copy test finds nothing even when the picture shows the words. For a scan, look at the page itself.

If the text is still there

Use a redaction tool that removes the text from the file and does not just draw over it. Adobe’s Redact tool does this in Acrobat Pro, and Redaction Studio works on your own device. Then run the test again on the new file. Do not send the first version.

A check that does the testing for you

Is It Really Blacked Out? reads your PDF file in your browser, looks for words that can still be recovered and checks for other leaks. It does not change the file, and a clear result means only that these checks found nothing.

Sources

• Adobe, remove sensitive content from PDF files
• Federation of American Scientists, post on the NSA guide “Redacting with Confidence” (20 January 2006)

Related guides

• Does this tool upload your file? How to tell before you use it
• Check first at work: a routine a team can share
• All guides