How to redact a PDF on Windows without paid software

The short answer

You don't need paid PDF software. Open Redact PDF in Edge, Chrome or Firefox, drop the file in, cover what you want hidden, and export. The PDF is processed on your computer inside the browser tab, so it's never uploaded, and there's nothing to install.

Step by step

1. Open Redact PDF and drag the PDF from File Explorer onto the page, or click to choose it.
2. Type the password if the file is protected.
3. Look through the highlighted details: emails, phone numbers, card numbers, IBANs and bank account numbers, IP addresses, dates of birth, and labelled names and addresses.
4. Use Find and redact for anything specific, such as a client name or a case number. Type it once to cover every match on every page.
5. Draw boxes over signatures, stamps and photos.
6. Export and save the new PDF next to the original with a clear name, such as adding "redacted" to the end.

Got a single page on screen? Take a screenshot, open the editor and press Ctrl+V to paste it straight in.

Common free methods that don't work

• Black highlighting in a word processor. The text is still there under the colour, and it survives saving as PDF.
• Shapes or comments added in a PDF viewer. These sit on top of the page and can often be moved or copied past.
• Changing the text colour to white or black. The words are still searchable.
• Light blur over numbers. Short numbers can sometimes be guessed back. See can blurred text be unblurred?

What works is removing the text from the page itself. Blur Document does that by rebuilding each page from pixels on export, then reading the result again with OCR to flag anything still visible.

If you redact PDFs regularly, keep a habit: work on a copy, export with a clear file name, and test the result before it leaves your computer.

Starting from a Word or Excel file

Blur Document doesn't open Word or Excel files directly. Save or export them to PDF first, then redact the PDF. How to redact a Word document covers this in more detail.

When you're done, test the result in the PDF Redaction Checker, which also lists leftover metadata, comments, form fields and attachments.