How to Redact Personal Information from a PDF — Truly Remove IDs and Account Numbers (Beware the Black-Box Trap)

There are plenty of times you need to hide sensitive data like ID numbers, account numbers, or amounts in a document you are submitting. But screenshotting it and covering it with a black rectangle in a paint app is actually dangerous. In a PDF, text is stored as data, so even if you lay a black box on top, the letters underneath remain intact. If the recipient drags to copy or presses Ctrl+F to search, the hidden information pops right back out — a classic cause of real-world data leaks. This guide covers how to redact by deleting the text data itself, so it can never be recovered.

Why a black box in a paint app is not enough

In a PDF, text is stored not as a photo but as text data. So even if you draw a black rectangle over it, that data does not disappear. If the recipient drags to copy or searches with Ctrl+F, the hidden content is right there, and in some viewers, simply clicking and moving the black box once exposes what is underneath. Proper redaction is not "covering," it is "erasing." The text and graphic objects under the box must actually be deleted from the PDF to be safe.

How to redact safely — 3 steps

1. Open the PDF — upload your file to PDF Eraser. The pages lay out on screen as they are.
2. Drag over what to remove — draw a box over the ID number, account number, amount, or other part to hide. You can choose black or white fill to match the document background.
3. Erase and download — apply, and you get a new PDF where the text and graphics under the box are actually deleted from the data. Open the result and drag or search that spot — nothing comes up.

Uploaded files are used only for processing and are not stored on the server.

Use it especially when

• Hiding amounts or unit prices when sending a contract or quote to a third party.
• Removing the back digits of an ID number from a copy of an ID or resident registration.
• Sharing a transaction statement with the account number hidden.
• Making a previously black-boxed file safe by truly erasing it again before submission.

To double-check after redacting

For an important document, open the redacted PDF from the recipient's point of view and drag and search that area to confirm nothing really shows. For a signed and sealed contract, you can also check whether the issued document has been tampered with via document verification.

Frequently asked questions

Q. Is the data really erased?
Yes. The text and graphic objects in the box area are deleted from the PDF and then filled with color. So they cannot be recovered by extracting, searching, or copying.

Q. How is this different from covering with a black box?
A black box only lays color over the letters, leaving the data underneath; this tool deletes the text data itself. So the content is not revealed even by dragging or searching.

Q. Is it free? Are my files stored?
It is free, and uploaded files are used only for processing and are not stored on the server.

Q. Can I use white instead of black?
Yes. You can choose black or white to blend naturally with the document background.