Guides

How to password protect a PDF (and remove a password)

Updated 21 October 2026

Tool for this guide: Protect PDF

Short answer: open protect PDF, add the file, type a password twice and press Protect PDF. The file is encrypted with AES-256, and anyone who opens it is asked for the password. To remove a password you know, use unlock PDF.

Step by step: add a password

1. Open protect PDF and add the PDF.
2. Type a password twice. Longer is safer.
3. Optionally tick Also block printing, copying and editing.
4. Download the protected PDF and keep the password somewhere safe.

The encryption is done by qpdf, a widely used open-source PDF library, running in your browser, so neither the PDF nor the password is sent anywhere.

Step by step: remove a password

1. Open unlock PDF and add the protected PDF.
2. Type its current password. Leave it empty if the PDF opens but blocks printing or copying.
3. Download the unlocked copy.

The unlock tool needs the correct password. It can't crack or guess forgotten passwords.

How strong is it?

AES-256 itself can't realistically be broken; the weak point is a guessable password. Make one with the password generator.

Open password vs restrictions

• The open password is the real protection: without it, the content can't be read.
• Restrictions (no printing, copying or editing) are respected by readers like Adobe Acrobat, but not every app enforces them.

Questions

What if I forget the password?

The PDF can't be opened without it, by us or anyone else. Store it in a password manager.

Does it work with Adobe Reader and phones?

Yes. AES-256 PDF encryption is supported by all current PDF readers.

Why unlock a PDF before merging or compressing?

Encrypted PDFs can't be read without the password, so other tools can't change them. Unlock first, then merge or compress.