Protect PDF
Add a password to a PDF so it cannot be opened without it. Strong AES-256 encryption.
Protect a PDF with a password
Drag and drop a PDF here, or choose a file from your device.
Processing happens in your browser. Your PDF is not uploaded.Upload a PDF to begin.
How to password protect a PDF
- Choose the PDF you want to protect.
- Type a password, then type it again to confirm.
- Click Protect PDF and download the encrypted file.
How strong is the protection?
The file is encrypted with AES-256, the strongest encryption the PDF format supports. Without the password the contents cannot be read. The protection is only as strong as the password, so use a long one that is hard to guess.
Frequently asked questions
What if I forget the password?
It cannot be recovered. Nobody, including us, can open the file without it, so store the password somewhere safe.
Is the password sent anywhere?
No. The encryption happens in your browser. Neither the PDF nor the password is uploaded.
Will the protected PDF open in any reader?
Yes, in any modern PDF reader, including Adobe Acrobat, Chrome, Edge, Preview on Mac and phone PDF apps. Readers more than about ten years old may not support AES-256.
Can I change or remove the password later?
Yes. Use Unlock PDF with the current password to remove it, then protect the file again with a new one.
Are my files uploaded to a server?
No. Your PDF is processed in your browser and never leaves your device.