QRix
Add a password to your PDF so only people with the password can open it.
This tool encrypts your PDF with a password. Once protected, the file cannot be opened, viewed or printed without entering the correct password. Encryption happens entirely in your browser — your file and password are never uploaded to any server. Ideal for sensitive documents like contracts, financial reports and personal records.
It's free, private and works right in your browser — no signup, no watermark.