PDF guide
How to Redact a PDF Properly (So the Hidden Text Is Really Gone)
Updated 27 September 2026 · 3 min read
Every few years a court filing or government report makes the news because someone “redacted” it with black rectangles — and readers copied the text straight out from underneath. A box drawn over text in many editors only covers it; the words are still in the file. Proper redaction removes the information itself. Here’s how to do it, and how to check that it worked.
Open the free Redact PDFCovering vs. redacting
| Covering (a shape drawn on top) | Redacting | |
|---|---|---|
| Looks hidden on screen | Yes | Yes |
| Text can be copied or searched | Often yes | No |
| Can be undone by deleting the box | Yes | No |
How KitWren redacts
In Redact PDF you drag black boxes over anything that must go. When you save with “Permanently remove redacted content” switched on — it is on by default — every page that has a redaction is converted into an image with the black boxes burned in. The original text, images and hidden layers on that page are discarded, so there is nothing underneath left to recover. Pages without redactions are kept exactly as they were.
The trade-off: text on a redacted page is no longer selectable or searchable, even outside the black boxes. For most documents being shared, that’s exactly what you want.
Step by step
- Open Redact PDF and choose your file.
- Drag a box over each item to remove — go a little beyond the edges of the text.
- Page through the whole document. Personal details often repeat in headers, footers and reference lines.
- Keep Permanently remove redacted content switched on.
- Download the redacted PDF and keep your original somewhere safe and separate.
What to look for
- Identity: names, signatures, dates of birth, addresses, phone numbers, email addresses.
- Numbers: tax file numbers, account and card numbers, Medicare or passport numbers, policy and customer IDs.
- Money: balances, salaries and transactions unrelated to the request.
- Other people: details of family members, colleagues or clients who didn’t agree to be shared.
- Barcodes and QR codes, which can encode the same details.
Check your redaction
- Open the redacted file and try to select or copy text inside a black box — nothing should be there.
- Search the document (Ctrl+F or ⌘F) for a word you removed.
- Run the file through PDF to text and read the output: redacted words must not appear.
- Zoom in to make sure no letters peek out at the edges of a box.
Don’t forget the hidden details
Redaction deals with what’s on the pages. A PDF also carries metadata — title, author, subject and keywords — which may include a name or a file title such as “J Smith termination letter”. Open the file in the PDF metadata editor to review and clear those fields before sharing.
Compressing, merging or re-saving a PDF does not redact anything — any text still in the file is carried across. Only redaction (or not including the page) removes it.
Scanned documents
A scan is already a picture, so a burned-in black box removes the content completely. The same checks apply: look for details that appear more than once, and remember that a scan may have been run through OCR previously, leaving invisible text behind the image — converting redacted pages to images removes that too.
Privacy
Documents that need redacting are, by definition, sensitive. KitWren redacts in your browser, so the original — with everything still visible — is never uploaded anywhere. This is general information; for legal disclosure obligations, follow your adviser’s or the court’s instructions.