Before you send a bank statement, a contract or a medical letter to someone, there are usually a few things they don't need to see: an account number, a home address, a colleague's name. The obvious fix is to draw a black rectangle over them, but that's a trap. In many PDF editors, the rectangle is just another layer sitting on top, and anyone can select it, delete it, or copy the text underneath. This tool does it the safe way: marked pages are turned into pictures with the black boxes burned in, so the information underneath is gone for good.
How to redact a PDF
- Open your PDF.
- On each page, drag over the text or numbers you want to hide. A black box appears. Drag again for more.
- Use the arrows to move through the pages. Remove a box with its cross, or press Clear this page.
- Choose the quality of the redacted pages (150 dpi is a good default).
- Click Redact & download.
Why covering text isn't redaction
There have been many embarrassing news stories where "blacked out" text turned out to be perfectly readable. Highlighting with a black color, drawing a shape or putting a label on top doesn't remove the words; they're still in the file, and copying and pasting will reveal them. The same goes for changing text color to white. True redaction removes the underlying content. Here, every page that has a box is redrawn as an image with the boxes burned in, and the original text of that page is not carried into the new file.
What you give up
Redacted pages become pictures. That means those pages can no longer be searched, selected or copied, and the file may be larger. Pages without any boxes are copied untouched and keep their real, searchable text. It's a fair trade for real security, and you can reduce the size afterwards by choosing a lower quality or running the result through Compress PDF. For readability, 150 dpi is plenty on screen; choose 200 or 300 only if the document will be printed in detail.
What to redact
- Account, card and ID numbers, which are the details thieves actually want.
- Home addresses and phone numbers of private individuals.
- Names of third parties in contracts or emails, where you don't have the right to share them.
- Salaries and pricing in documents shared with someone who shouldn't see them.
- Medical details in letters or reports passed to non-medical readers.
Under European data protection rules, sharing only the information a person needs, called data minimization, is a legal principle, and redaction is a practical way to follow it.
A checklist before you send
After redacting, open the result and check every marked page. Try to select text in the redacted area: it should be impossible. Check that the boxes cover the whole text, including descendants of letters like g and y, and that nothing else sensitive appears in headers, footers or margins. Names also sneak in via the file's properties; use the PDF metadata editor to look at, and remove, the author and software fields. If you're sharing the document widely, consider also adding a watermark that identifies the recipient.
Working with other tools
If the document is long and you only need to share some pages, take out the rest with Delete PDF Pages or Split PDF before redacting; it's less work and leaves less to get wrong. If you want the redacted pages locked in alongside the rest, Flatten PDF turns everything into pictures. And if you need to give your signature to the final version, sign it as the last step.
The whole process happens in your browser. The document you're hiding things from is never uploaded to us, which is rather the point of redaction.
Troubleshooting
If a box doesn't cover everything, draw another one over the gap; boxes can overlap. If you drew one in the wrong place, press its cross to delete it. If the redacted pages look blurry, increase the quality to 200 dpi and save again. If the file is much larger than the original, lower the quality, or compress it afterwards. Remember that only pages you've marked change, so a long document with a few boxes will stay mostly as it was.
A worked example
You're sending a landlord a bank statement as proof of income, but it shows every transaction. Mark the account number, your address and the lines for unrelated payments, leaving only your salary credit visible. Save at 150 dpi, open the result, and try to select text in the covered areas: nothing can be selected. You've shared what's needed, and nothing more.
Finally, keep your unredacted original somewhere secure, and never send both the original and the redacted version to the same person. Name the files so there is no confusion, for example "statement-REDACTED.pdf", and double-check the attachment before you press send; mixing them up defeats the whole exercise.
A redacted page can also be turned into an image for sharing in a chat or a presentation using PDF to JPG, which is a handy way to show the result without sending the PDF itself.