Redaction
How to redact a PDF – so the text is really gone
A bank statement for a landlord, a payslip for an authority, files for a data access request: before a PDF goes out, names, account numbers or amounts need to disappear. A black box often isn't enough – the text underneath can still be copied. Here's how to do it safely.
Get started: open the PDF, mark or search the sensitive parts, save it safely redacted. Free and no upload.
Redact a PDFThe problem with black boxes
A PDF is made of layers: text, images, drawings. Drawing a black rectangle in Word, Acrobat Reader, a preview app or with the highlighter of a PDF app only adds another layer on top. The text underneath is still there.
- Select and copy brings the “redacted” text back.
- Search finds it.
- Anyone opening the PDF in an editor can simply move the box aside.
Such mishaps have made headlines again and again – in court filings, government documents and company papers. The mistake is always the same: covered instead of removed.
Only what's no longer in the file is safe. There are two ways: real redaction features that delete the text from the PDF (e.g. in Acrobat Pro), or turning the affected pages into images after drawing the boxes. This tool does the latter.
How to check a redaction
- Open the redacted PDF, press Ctrl + A (Mac: ⌘ + A) and paste into a text editor. If the redacted text shows up, it's still there.
- Search for a redacted word with Ctrl + F.
- Open the file in a second app – some viewers display comments and shapes differently.
After redacting with this tool, step 1 returns no text at all on redacted pages: the page is an image.
Redact safely in four steps
- Open the PDF. Drop the file into Redact PDF. All pages appear one below the other.
- Draw boxes. Hold the mouse button and drag a rectangle over everything that should disappear. Click to select, drag the corner to resize, Del to delete.
- Pick the quality. 200 dpi is fine for screen and print; 300 dpi for very small type; 150 dpi for small files.
- Save. “Save redacted PDF”. Every page with a redaction is rebuilt as an image with the black bar burned in. Pages without redactions stay unchanged.
Draw boxes or search for names – redacted pages become images, and the text underneath is gone.
Find names, IBANs and e-mails automatically
In long documents, marking every name by hand is tedious. The tool's search finds every occurrence at once:
| Search | Finds |
|---|---|
| Free text | Every occurrence of a word or name, ignoring case |
| E-mail addresses | Anything like name@domain.com |
| IBANs | Account numbers such as DE02 1203 0000 0000 2020 51, with or without spaces |
| Phone numbers | Numbers with area code, e.g. 030 1234567 or +49 30 1234567 |
| Dates | Dates written as DD.MM.YYYY, such as birth dates |
“Redact all matches” puts a box over every hit. Check the pages afterwards: search works on the PDF's text layer. Scanned documents don't have one – draw the boxes by hand there. Text that wraps across two lines isn't always found completely either.
Checklist before sending
- Look through every page – including headers, footers, stamps, signatures and barcodes.
- Indirect clues: case numbers, customer IDs, letterhead addresses or the length of a redacted name can reveal who's meant.
- File name – “Statement_Jane_Doe.pdf” defeats the purpose.
- Metadata: this tool doesn't carry over the original title and author. For other tools, see Remove PDF metadata.
- Double-check: copy the text and search as described above.
White instead of black? The tool can also draw white boxes. Then the spot doesn't stand out – useful e.g. for forms that will be filled in again. For documents going to authorities or courts, visible black bars are more common because they show that something was removed.
Redact your PDF safely
Draw boxes or search names, e-mails and IBANs, save – the text underneath is really gone. Free, no upload.
Frequently asked questions
Is redacting with this tool really safe?
Every page with a redaction is rebuilt as an image with the bar burned in. The original text of that page is no longer in the file.
Why is redacted text in Word or Reader still readable?
Because they usually just place a black rectangle over the text. The text stays underneath and can be copied or searched.
Is my PDF uploaded?
No. Redaction happens entirely in your browser.
Can I still select text after redacting?
Not on redacted pages, because they're images. Pages without redactions stay unchanged and searchable.
Does the file get bigger?
Redacted pages become images and need more space than text. 150 dpi keeps the file small; 200 dpi is a good compromise.
Does search work on scanned PDFs?
No – a scan contains no text, only an image. Draw the boxes by hand on scans.
Can I undo a redaction?
In the tool, yes, as long as you haven't saved. In the saved file, no – that's the point. Keep the original somewhere safe.
Sources
- Art. 15 GDPR – Right of access (rights of others when handing out copies, para. 4).
- PDF.js and pdf-lib – the open-source libraries the tool uses to render and save.