How to Redact a PDF for Free (No Sign-Up, No Watermark)
By Henry Stein · September 5, 2026
Before you send a document on, you often need to hide part of it — an ID number, bank details, a home address, a salary figure, someone else's personal information. Redacting a PDF lets you black out exactly what shouldn't be seen. And you can do it without installing anything or uploading the very file you're trying to protect.
This guide shows you how to redact a PDF for free using StylusPDF. The whole thing runs in your browser, so your document never gets uploaded anywhere. It stays on your device from start to finish.
Redact a PDF in four steps
- Open the Redact tool. Head to the StylusPDF Redact page and click Open PDF, then choose your file.
- Cover what needs hiding. Draw a box over each piece of sensitive text or any area you want blacked out.
- Check every page. Scroll through the whole document and make sure nothing sensitive is still showing before you save.
- Download. Click Download and your redacted PDF saves straight to your device. No account, no watermark.
That's it — usually a minute or two, depending on how much you're hiding.
What "redaction" really means
There's a mistake that's leaked more confidential documents than almost anything else: drawing a black rectangle over text in a PDF viewer and assuming the text is gone. Often it isn't. The box is a shape sitting on top of the page, and the original text can still sit in the file underneath — selectable, copyable, or revealed by deleting the box. Courts, companies, and government departments have all published "redacted" files that were undone this way in seconds.
StylusPDF's Redact tool covers whatever you select with a solid black box, and it shows you an on-screen reminder about exactly this point. Covering an area is genuinely enough when your goal is simply that a reader doesn't see the information. But a covered box is not the same as deleted content: for legal, medical, financial, or otherwise highly sensitive material — anything where the hidden data must not be recoverable by anyone — you'll want to go one step further and flatten the file so nothing survives underneath.
The simplest way to do that with StylusPDF: after you've placed your boxes, run the result through PDF to Image and then Images to PDF. Converting each page to a picture turns the whole page into flat pixels, so there's no hidden text layer left to recover. Whenever it matters, finish with the check the professionals do: open your file and try to select or search for what you hid. If nothing comes up, you're good to share.
Your file never leaves your device
There's an irony in most online redaction tools: to hide your sensitive information, they first upload the whole unredacted file to their server — exposing the exact thing you're trying to protect.
StylusPDF works differently. Every tool runs client-side, directly in your browser. Your PDF is never uploaded, never stored, and never seen by anyone but you. When you close the tab, it's gone.
Redact your PDF now
Need to share a document without giving everything away? The Redact tool is free to use — open your file and you'll have it covered in a minute or two.