Redacting a document: making personal data safely unreadable
To "redact" a document means making sensitive information unreadable before you share it. Governments do it when answering freedom-of-information requests, employers when sharing a file, and individuals when they have to send in a copy of a payslip, for example. It looks simple: put a black box over it and you're done. But that is exactly where it often goes wrong.
Why a black box is not always safe
If you place a black rectangle over text in Word or a PDF viewer, the text is often still there underneath. Anyone who moves the box, or selects and copies the text, can read everything. A black highlighter in Word is just formatting too. There are countless examples of "redacted" reports whose secret text became visible with a single copy and paste.
Other pitfalls:
- Metadata: the author's name, the organisation or earlier versions remain in the file;
- Track changes: deleted text can still be recovered;
- Scans: a scanned page with OCR contains a hidden text layer;
- Forgotten places: headers, footnotes, attachments and file names.
How to redact a document properly
1. Really remove the text
Replace sensitive data in the text itself instead of just covering it. A label such as [NAME] or [ID NUMBER] shows that something was removed without the reader losing the thread.
2. Use real redaction features
Professional PDF software has a "redact" function that removes the underlying text. An ordinary drawing tool does not.
3. Export again
Save the result as a new file, or paste the cleaned text into a blank document. That way you don't carry over old metadata or version history.
4. Test the result
Select all text (Ctrl+A), copy it and paste it into Notepad. If you can still see a name or number there, the document is not safe.
What should you redact?
Anything that can directly or indirectly identify someone: names, addresses, ID numbers, IBANs, dates of birth, phone numbers, email addresses, signatures, licence plates and photos. When sending a copy of an identity document, black out anything the recipient does not need and, where possible, add a note on the copy stating its purpose and the date.
Don't upload to unknown sites. Sending a document containing personal data to an online "redact" service means sharing that data with yet another party. VerumVault works entirely locally in your browser, so your document goes nowhere.
Automatic redaction with VerumVault
VerumVault automatically searches your text for personal data such as names, addresses, postcodes, IBANs, phone numbers and email addresses, and replaces them with labels. Because the data really disappears from the text, nobody can recover it by moving or copying something. Detection is currently optimised for Dutch documents, so always check the result yourself before sharing it.
Anonymise your document for free with VerumVault →Runs locally in your browser · no upload · no account · optimised for Dutch documentsFrequently asked questions
What is the difference between redacting, blacking out and sanitising?
In practice they mean the same thing: removing sensitive information from a document before you share it. What matters is that the text is really deleted, not just visually covered.
Is a black highlight in Word safe?
No. A black highlight or shape in Word only covers the text. The text stays in the file and can be copied. Replace the text itself or use a real redaction feature.
Can I redact a PDF without uploading it?
Yes. With VerumVault you paste the text or open your file in the browser. Processing happens locally on your own device.