Protect a PDF with a password
Encrypt your PDF with AES-256 (qpdf) without it leaving your device: the password will be required to open it.
Your files never leave your device
How to password-protect a PDF
- 1
Upload the PDF
The file never leaves your browser.
- 2
Pick a password
Type it twice to avoid typos.
- 3
Download the encrypted PDF
AES-256: the password is required to open it.
Why use this tool
Real encryption
AES-256 with qpdf, the industry standard.
Total privacy
Encryption happens on your device, not on a server.
Compatible
The encrypted PDF opens in Acrobat, browsers and phones.
No tricks
No watermarks, no signup, no weird limits.
Frequently asked questions
Which encryption is used?
AES-256, the strongest in the PDF standard, applied with qpdf (the reference tool) compiled to WebAssembly.
What if I forget the password?
There is no way to recover it: nobody can open the PDF without it. Keep it in a password manager.
Does my password travel to a server?
No. The whole process, password included, stays in your browser.
Can I remove the password later?
Yes, with the Unlock PDF tool, as long as you know the password.