How to use Lock PDF
- Drop the PDF you want to protect.
- Type a password twice.
- Choose what readers may do: print, copy, comment, change.
- Press Lock PDF and download the protected file.
About this tool
Add a password that's needed to open the PDF, using strong AES-256 encryption — the same strength Adobe Acrobat uses. You can also choose whether readers may print, copy text, add comments or change the document. The password is used only on your device; it isn't sent or stored anywhere, so keep it safe: a lost password can't be recovered.
- AES-256 encryption
- Choose print, copy and edit permissions
- Optional separate permissions password
- The password never leaves your device
Questions
How secure is a password-protected PDF?
With AES-256 and a long password it is very hard to open without the password. Use at least 8–12 characters with words and numbers that aren't easy to guess.
What happens if I forget the password?
It can't be recovered — not by us, not by anyone. Keep a copy of the unlocked file or store the password safely.
Can I remove the password later?
Yes, with Unlock PDF, as long as you know the password.