Modifying this control will update this page automatically
    
Password-protect a PDF in Preview on Mac
You can give a PDF a password that everyone must enter to open the file. The password is used to encrypt the file.
- In the Preview app  on your Mac, open the PDF you want to password-protect. on your Mac, open the PDF you want to password-protect.
- Choose File > Export, then select Encrypt. 
- Type a password, then retype it to verify the password.