Help Center › Mac › Security

Protect a PDF with a password

Add, change or remove a password on a PDF. Open password-protected files.

iOS Android Mac Windows Web
Applies to macOS 14 Sonoma or later

Kiwi PDF can add a 256-bit AES password to any PDF, change an existing password, or remove it entirely.

Add a password

  1. With the PDF open, choose File › Password… (or ••• › Protect in the top bar).
  2. Type the new password and type it again to confirm.
  3. Click Set Password. The file is encrypted when it is saved.
    The Set Password dialog23
    The Set Password dialog
The password uses AES-256 encryption. There is no way to recover a forgotten password — keep it somewhere safe.

Open a password-protected PDF

When you open a protected PDF, Kiwi PDF asks for the password before showing the content. Type the password and tap/click Open. The document is decrypted locally — the password is never sent to a server.

Change or remove a password

Open the protected PDF, then choose File › Password… again (Web: Protect). Leave the field blank to remove the password.

What the password protects

The password encrypts the entire PDF file. Anyone who tries to open the file in any PDF app will need the password. It does not protect the file from being shared or forwarded — it only protects its contents from being read without the password.