How to redact a PDF and black out text
Quick answer: To black out text in a PDF, use a redaction tool rather than a drawn box. In Quick PDF, open the file with Redact, drag over the text you want hidden or tap a line, then download. The redacted pages are rebuilt so the hidden words are removed from the file, not just covered.
Sign in with Google or email and start editing. Saving your file starts a free trial: 7 days on yearly ($29.78/yr) or 2 days on monthly ($2.99/mo). Cancel anytime. 🔒 Your file stays on your device.
Before you share a bank statement, a contract, a medical bill or a screenshot of a document, you may need to hide names, account numbers, addresses or signatures. The catch is that many ways of blacking out text only hide it on screen. The words are still in the PDF, and anyone can copy them out.
This guide shows how to black out text so it is actually removed, and how to check your work before you send it.
Black out (redact) text in a PDF with Quick PDF
- Open the Redact tool Sign in at quickpdfapp.com and open Redact PDF, or pick Redact in the editor toolbar.
- Choose your PDF Select the file from your device. It is processed in your browser and not uploaded.
- Mark what to hide Drag a box over each item, or tap a line to mark the whole line. Zoom in for small items like account numbers.
- Review every page Scroll through the whole document. The same details often repeat in headers, footers and on later pages.
- Download the redacted PDF Tap Download. Pages with redactions are rebuilt so the hidden text is gone.
- Test the result Open the new file and try to select or search for a hidden word. Nothing should be found under the black boxes.
Why a black box or highlighter is not enough
Drawing a black rectangle, using a black highlighter, or changing text colour to black on black only changes what you see. The original words stay in the file. Anyone who receives it can often:
- select the area and copy and paste the text into a note,
- use search to find a hidden name or number,
- move or delete the shape in an editor to reveal what was underneath.
This is how private details leak from documents that look properly blacked out. Real redaction removes the content itself. In Quick PDF, each page that contains a redaction is redrawn as an image with the black boxes burned in, so the hidden words no longer exist in the file.
What to black out (a checklist)
- Full account, card and routing numbers (many people keep only the last four digits visible).
- Social Security numbers and dates of birth.
- Home addresses, phone numbers and personal email addresses.
- Signatures, if the document is only being shared for information.
- Names of other people, such as tenants, patients or children.
- Barcodes and QR codes, which can contain account details.
- Notes and comments that were added to the file.
Check with whoever asked for the document what they need to see. A landlord might need your income figures but not your full account number.
What changes on redacted pages
Because redacted pages are rebuilt as images, the text on those pages can no longer be selected, copied or searched. Pages you did not redact are left as they were. If you need the rest of a page to stay selectable, consider extracting just the pages you need with Extract pages and redacting only those.
Redacted pages can make the file a bit larger. If it is too big for email afterward, compress it before sending.
Redacting on a phone or computer
The steps are the same everywhere because Quick PDF runs in the browser. On iPhone, save the PDF to the Files app first (from Mail, tap the attachment, then the share icon, then Save to Files), and on Android save it to Downloads. On a Mac or Windows PC, the file is usually in your Downloads folder already.
On a small screen, pinch to zoom before dragging so the box covers the whole number and nothing else. Tapping a line is quicker for full lines such as an address. When you are done, Share on a phone sends the redacted file straight to Mail or Messages.
Black out vs. white out
White-out hides words under a white area so you can type a correction on top. It is a visual cover, meant for fixing typos and reusing templates, and the original text stays underneath. Redact removes the content. For anything private, redact. The difference is explained in how to white out text in a PDF.
Common redaction mistakes
- Missing repeated details. An account number may appear on every page header. Check each page.
- Forgetting file details. The file name itself can contain a name or account number. Rename the downloaded file before sharing.
- Leaving comments in. A sticky-note comment or a highlight added earlier can repeat the very detail you hid. Look for notes on every page before redacting.
- Sending the wrong copy. Your original file is unchanged; make sure you attach the downloaded, redacted one.
- Over-redacting. Blacking out everything can make a document useless for whoever needs it. Hide only what they do not need.
For extra protection when sending, you can also add a password; see how to send a PDF securely.
Questions people ask
How do I permanently black out text in a PDF?
Use a redaction tool that removes the content, not a drawn shape. In Quick PDF, Redact rebuilds each redacted page as an image with the boxes burned in, so the hidden words are no longer in the file and cannot be copied or searched.
Can blacked-out text in a PDF be recovered?
If it was hidden with a shape, highlighter or black text colour, often yes, because the original text is still in the file. If it was properly redacted so the content was removed, there is nothing underneath to recover.
How can I check that redaction worked?
Open the downloaded file, try to select text under a black box, and search for a word you hid. Nothing should be selected or found. Also try copying the whole page into a note to make sure the hidden details do not appear.
Can I black out text on my phone?
Yes. Open quickpdfapp.com in your phone's browser, open the file with Redact and drag your finger over each item. Zoom in for small numbers. Then download or share the redacted copy.
Can I black out part of a scanned document?
Yes. Redact works on scans and photos too. Drag over the area you want hidden. Since a scan is already an image, the redacted page looks the same as before except for the black boxes.
Can I undo a redaction after downloading?
No. Once the redacted file is downloaded, the hidden content is gone from that copy. Your original file on your device is unchanged, so keep it somewhere safe if you might need the full version later.
Do I have to pay to use Quick PDF?
You can open a PDF and edit, sign or fill it after signing in with Google or email. To download, print or share the finished file you start a subscription with a free trial: 7 days on the yearly plan ($29.78 per year) or 2 days on the monthly plan ($2.99 per month). You are charged when the trial ends unless you cancel, and you can cancel anytime.
Sign in with Google or email and start editing. Saving your file starts a free trial: 7 days on yearly ($29.78/yr) or 2 days on monthly ($2.99/mo). Cancel anytime. 🔒 Your file stays on your device.