Guide · PDFs on Mac
Black out text in a PDF, for real
A black rectangle drawn over a line of text hides it on screen, and that is all it does. The words are still in the file: anyone can select them, copy them or find them with search. Here is how to black out text in a PDF so it is actually removed, on your Mac and without uploading the document.
Get BlurData for Mac How to do itSelect the bar, copy, paste:
Thomas Reeve, 14 Acacia Avenue
Select the bar, copy, paste:
nothing to paste
A black box is not a black out
Most PDF editors, Preview included, let you draw a filled rectangle or a thick black highlight over a sentence. That shape is a separate layer sitting on the page. The text below it is untouched, which is how names and account numbers keep leaking out of court filings and official releases: someone selects the bar, copies, and pastes the "hidden" text into an email. We collected some of the best known cases in real-world redaction failures.
Blacking out text properly means two things at once: the text is taken out of the PDF's content, and the area is covered so the layout still shows where something was removed. That is what BlurData's Redact mode does.
How to black out text in a PDF with BlurData
Drop the PDF into BlurData
One file or a whole folder. Scanned PDFs and photos of documents work too: every page is read on your Mac.
Let it find the sensitive data
Names, emails, addresses, amounts, account numbers and IBANs are highlighted on every page. Pick a document preset, such as bank statement, payslip or medical record, to catch the identifiers specific to that document.
Black out anything else by hand
Double-click a word to hide it on that page or everywhere it appears, or draw a box over a line, a signature or a whole paragraph. Remove a detection that should stay visible.
Pick the color and export
Black, or any color you prefer. With Save All as One PDF (keep text selection), the rest of the document stays searchable and only the parts you chose are gone from the file.
Other ways to black out text in a PDF
For a couple of words in a short file, Preview's Redact tool does the job for free: choose Tools > Redact, drag over the text, save. The full walkthrough is in how to redact a PDF on Mac. Here is how the usual options compare.
| Method | Text removed from the file | Finds the data for you | Document stays on your Mac |
|---|---|---|---|
| Black box or highlighter in a PDF editor | No, it is still underneath | No | Yes |
| Preview, Tools > Redact | Yes | No, one box at a time | Yes |
| Online PDF tools | Varies | Varies | No, the file is uploaded |
| BlurData | Yes | Yes, plus presets and your own patterns | Yes |
Check that the text is gone
Open the exported PDF and press Cmd+F. Search for a name or a number you blacked out. Then drag across one of the black bars, copy and paste into a note. If search finds nothing and nothing pastes, the text is out of the file. Press Cmd+I in Preview too: the document properties can still carry an author or a client name, and BlurData's export does not carry over the original metadata. Do the check once and you will know what to expect every time after.
Remove text from a PDF permanently: when it matters
Before you send it
Contracts, quotes and statements going to someone who should not see every name and number in them. Redacting a bank statement before it goes to a landlord is a common one.
Before you file or publish it
Court filings, public records and reports where names, addresses and case numbers must not stay in the file.
Before you give it to an AI
If the document still has to make sense, switch to Pseudonymize: names become labels like [PERSON_1] instead of black bars. See anonymize documents for AI.
Frequently asked questions
Does drawing a black box over text in a PDF remove it?
No. A black rectangle or a black highlight is an extra object placed on top of the page. The text underneath stays in the file, so it can be selected, copied and found with search. To black out text for real, the text has to be taken out of the PDF's content, which is what a redaction tool does.
How do I check that blacked-out text is really gone?
Open the exported PDF, press Cmd+F and search for a word you blacked out. Then drag across the black bar, copy and paste into a text editor. If search finds nothing and nothing pastes, the text is no longer in the file.
Can I black out text in a PDF for free on a Mac?
Yes, with Preview: choose Tools > Redact and drag over each piece of text, then save. It is manual, so every name and number is a separate box and there is no batch mode. BlurData finds the sensitive data for you and handles long documents and whole folders.
Can I black out just one word or one line?
Yes. In BlurData, double-click a word and choose whether to hide it only there or everywhere it appears, or draw a box over a line, a signature or any area of the page.
Does it work on scanned PDFs?
Yes. BlurData reads scanned pages with on-device OCR, finds names, numbers and addresses, and covers them. In a scan the text is part of the image, so in the exported file the covered area is replaced pixels and cannot be brought back.
Will the rest of the PDF stay searchable?
Yes, when the PDF has a text layer. Export with Save All as One PDF (keep text selection) and the rest of the document can still be selected and searched, while the blacked-out words are gone from the file.
Can I black out text in a PDF online?
Many websites offer it, but you have to upload the document to their servers first. For contracts, statements or medical files that is a step worth skipping. BlurData works on your Mac and the PDF never leaves it.