Password Protect PDF
Lock a PDF with a password using strong AES-256 encryption. The file can only be opened by someone who knows the password.
How to password Protect PDF
- 1Add your PDF
Drop the PDF you want to protect.
- 2Set a password
Type a strong password twice.
- 3Download
Click Encrypt PDF and save the protected file.
Features
AES-256 encryption
The strongest standard PDF encryption, supported by Adobe Acrobat and modern readers.
Password stays private
Your password is used in this page only and never stored.
Works everywhere
Open the protected file in any PDF reader by entering the password.
Private by design
Editing runs in your browser with open-source libraries. Files are checked for size and pricing, but the PDF processing itself happens on your device.
Frequently asked questions
How do I put a password on a PDF?
Add the PDF, enter and confirm a password, then click Encrypt PDF.
What if I forget the password?
It cannot be recovered. Keep the password in a password manager.
Can I protect an already encrypted PDF?
No. Unlock it first, then protect it with a new password.
Why does the first use take longer?
The encryption engine (pypdf) downloads once, then runs locally.
Is this tool free?
Files under 200 KB are free. Larger batches have a one-time price based on total file size, shown before you process anything.