Can I redact a PDF without Adobe Acrobat?

Yes. Cachety is free, works in any modern browser, and really removes what you mask instead of just covering it.

Can redacted text be recovered?

If it was only covered with a shape, often yes. With Cachety, the masked area is removed from the file itself, so there is no hidden text left to recover.

Do I have to add a watermark to redact?

Cachety is built around watermarking, so it is designed for adding a short text as well. A watermark with the purpose, recipient and date is good practice anyway, and makes any leaked copy traceable.

How big a PDF can I redact?

Up to 200 MB per file and 500 pages per PDF.

How to properly redact a PDF or image for free

Updated 11 October 2026

Drawing a black box over a number looks like it hides it. In many PDFs, though, the text is still sitting underneath and anyone can copy it. Here is how to redact properly, for free.

Example watermark

Proof of address – Brightwater Energy – 11/10/2026

Why a black box is not always enough

A PDF is made of layers. When you draw a black rectangle in many PDF editors, you are only adding a shape on top. The original text is still in the file. Someone can select it, copy it and paste it somewhere else, and there it is again. This has caught out plenty of people and organisations over the years. It is an easy mistake to make, because on screen everything looks fine.

A quick test for any redacted PDF: try to select the text under the black box, or use your PDF reader's search to look for a word you hid. If it is found, the redaction did not work.

How Cachety redacts

Cachety does not lay a box on top. It rebuilds each page as a picture, with the masked area blacked out for real. The hidden text is gone from the file, as is the selectable text layer and the file's hidden information, such as its author or the GPS location of a photo.

1Open cachety.com in your browser. No sign-up is needed.
2Drop your PDF or image onto the page. JPG, PNG, HEIC and other common formats work too.
3Type a short watermark, such as the purpose, recipient and date, or press the button to add today's date.
4On the preview, draw rectangles over everything you want to hide.
5Check the preview on every page, then download your redacted copy.

What people usually redact

Bank account numbers and sort codes.
National Insurance numbers on payslips and letters from HMRC.
Passport and licence numbers, when the recipient only needs your name and photo.
Medical details, or information about children or other family members.
Signatures, when a copy is just for information.

Private by design

Many free online redaction tools ask you to upload your document to their servers. That is a strange thing to do with the very information you are trying to protect. Cachety works the other way round: your file stays on your device, nothing is sent anywhere, and the page even keeps working in airplane mode once it has loaded.

Since the redacted copy is rebuilt as images, you will not be able to search or copy its text. That is the point, but keep your original somewhere safe in case you need it later.

Redaction and watermarking work well together, but neither is a guarantee. Someone can still photograph what they can see. Hide what is not needed, watermark what you send, and only send it to people you trust.

Frequently asked questions

Can I redact a PDF without Adobe Acrobat?: Yes. Cachety is free, works in any modern browser, and really removes what you mask instead of just covering it.
Can redacted text be recovered?: If it was only covered with a shape, often yes. With Cachety, the masked area is removed from the file itself, so there is no hidden text left to recover.
Do I have to add a watermark to redact?: Cachety is built around watermarking, so it is designed for adding a short text as well. A watermark with the purpose, recipient and date is good practice anyway, and makes any leaked copy traceable.
How big a PDF can I redact?: Up to 200 MB per file and 500 pages per PDF.