Add strong password protection to any PDF file. Uses AES-256 encryption — the same standard used by banks and governments — to prevent unauthorized access.
Why use Protect PDF?
AES-256 encryption, the strongest PDF encryption standard
Set a user password required to open the file
Compatible with Adobe Acrobat, Preview, and all major PDF readers
No copy of your password is stored anywhere
How it works
Upload your PDF
Enter a password
Download the encrypted PDF
Frequently asked questions
What happens if I forget the password?
There is no recovery option — AES-256 encryption cannot be brute-forced in practice. Store your password securely before downloading.
Can I protect a PDF that is already password-protected?
Upload a locked PDF and the tool will ask for the current password to unlock it first, then apply your new password.
Is this the same encryption as ilovepdf or Smallpdf use?
Yes — AES-256 with PDF revision 6 is the current PDF specification maximum and is the same used by all major PDF tools.