Protect PDF
Add AES-256 password protection required to open your PDF.
The interactive tool loads here when JavaScript is enabled. Files are processed locally in your browser.
How to use Protect PDF
- Select a PDF.
- Enter and confirm a strong password.
- Process locally and download your new PDF.
Features
- AES-256 encryption with a password required to open the PDF.
- Password confirmation to prevent typos.
- Encryption runs locally; the file is not uploaded.
- Content and layout are unchanged.
Supported formats and limitations
Input and output: PDF.
- Already-encrypted PDFs must be unlocked first.
Frequently asked questions
How strong is the protection?
AES-256 is a strong standard. The real strength depends on your password, so use a long, unique one.
What if I forget the password?
There is no recovery. Keep the password in a password manager.
Will every PDF reader open it?
Modern readers support AES-256. Very old software may not open the file.