Home › File & PDF Tools › Redact PDF Online
Redact PDF Online
Before you share a bank statement, a marksheet or an ID proof, hide the parts strangers do not need: account numbers, Aadhaar or PAN numbers, addresses, marks. This free tool lets you draw black boxes over anything sensitive, on any page, right in your browser — your file is never uploaded. It offers two ways to finish: a quick Cover mode that paints boxes over the page, and a Secure mode that rebuilds the whole PDF as pictures, so the hidden words are removed from the file completely. For anything truly sensitive, use Secure mode — the difference matters, and it is explained honestly below.
Page 1 of 1
Drag on the page to draw a black box. Boxes are remembered separately for every page — move through the pages and cover everything sensitive before you apply.
No boxes on this page yet.
Your file is processed entirely on your device and is never uploaded. The PDF.js reader library used to display pages is loaded from the cdnjs CDN (cdnjs.cloudflare.com); only the library travels over the internet, never your document.
How to use this redact tool
- Drop your PDF into the box, or click to choose it. The first page appears on screen.
- Drag across anything sensitive — a number, a name, an address — to draw a black box. Draw as many boxes as the page needs.
- Move to the next page with the page buttons and repeat. Boxes are kept separately for each page.
- Choose the mode: Secure for anything truly private (recommended), Cover only when appearance is all that matters.
- Press "Apply redactions and download", then open the result and check every page before you share it.
Cover mode vs secure mode — please read this
In Cover mode, the tool paints solid black boxes onto the pages and saves the file quickly. The page looks redacted, and the rest of the document stays sharp, small and copyable. But the words under the boxes are still inside the file — anyone who receives it can copy the text out from underneath the box. Cover mode is fine for hiding something from a casual glance, and for nothing more.
In Secure mode, every page is turned into a flat picture with your black boxes burned into the picture, and a new PDF is built from those pictures alone. There is no text layer left anywhere in the file, so there is nothing under the boxes to recover. The price is a bigger file, text that can no longer be selected or searched, and slightly softer print — the normal, accepted price of a real redaction.
Worked example
Imran must send his bank statement to a landlord as address proof, but the statement shows his full account number and his Aadhaar number on page 1. He opens the file here, drags one box over the account number and another over the Aadhaar number, and leaves the mode on Secure. He presses apply: the tool rebuilds all 4 pages as pictures with the two boxes burned in. The landlord can read his name, address and the bank's name — and nothing else. Imran checks the download page by page, then sends it.
Which mode should you choose?
| Question | Cover mode | Secure mode |
|---|---|---|
| Looks blacked out on screen | Yes | Yes |
| Hidden text can still be copied out | Yes — it is still in the file | No — the text layer is gone |
| Rest of the text stays selectable | Yes | No — pages become pictures |
| File size and print sharpness | Nearly unchanged | Bigger file, slightly softer |
| Right choice for IDs, account numbers, marks | No | Yes |
Frequently asked questions
Is the black-box (cover) mode safe for sensitive information?
No. In cover mode the box is only painted over the text — the words are still stored in the file and can be copied out by anyone who receives it. News organisations have embarrassed themselves exactly this way. Use secure mode for account numbers, ID numbers, marks, medical or legal details — anything you truly need gone. Secure mode rebuilds every page as a picture, so there is no text left to recover.
Why does the secure-mode file get bigger and lose selectable text?
Because secure mode replaces every page with a picture of that page. Pictures are larger than text, and a picture of words is not words — readers cannot select, copy or search them, and printing is a little softer. That loss is precisely what makes the redaction real: the hidden information is removed, not merely covered.
Are my PDFs uploaded to a server?
No. Your document is opened, displayed and rebuilt entirely in your browser on your device. The only thing downloaded from the internet is the PDF.js reader library, which loads from the cdnjs CDN — your file itself is never sent anywhere, and the redacted download is created on your device.
Can I redact boxes on many pages?
Yes. Move through the document with the Previous and Next buttons; the tool remembers the boxes for each page separately and shows how many boxes the current page has. When you press apply, every page's boxes are applied — in secure mode to the rebuilt picture of that page, in cover mode as painted boxes.
Does redaction work on scanned PDFs?
Yes, in both modes — a scan is already a picture on each page, so drawing boxes over parts of it works the same way. Secure mode is still the safer choice for scans you share publicly, because it also removes any hidden text layer that scanning software (OCR) may have added behind the picture.
I made a box in the wrong place. Can I fix it?
Before applying, yes: 'Undo last box on this page' removes the most recent box, and 'Clear boxes on this page' removes them all for that page, so you can draw them again. After you have applied and downloaded, the change is final in that copy — but your original file was never touched, so you can simply start again from the original.