
Password-protect a PDF in Preview on Mac
You can protect a PDF with a password that must be entered to open the file. You can also set a password to manage access to features such as printing, copying text and adding annotations.

Set a password for opening, printing or changing a PDF
- In the Preview app  on your Mac, open a PDF. on your Mac, open a PDF.
- Choose File > Export. - If you want to create a password-protected copy and keep the original PDF unencrypted, enter a new name for the PDF. 
- Click the Permissions button, then do any of the following: - Set a password for opening the PDF: Select Require Password To Open Document. Enter a password, then retype it to verify. 
- Set permissions: Select the tickbox next to an action to allow printing or changes without the owner password. Leave the tickbox unselected to require the owner password. 
 
- Enter a password in the Owner Password section, then retype it to verify. It can be the same as or different from any password you created in step 3. 
- Click Apply, then click Save. 
Changes take effect the next time the PDF is opened.
Manage permissions for a PDF
After setting an owner password for a PDF, you can change password-protection options or create a new password. Changes take effect the next time the PDF is opened.
- In the Preview app  on your Mac, open a PDF. on your Mac, open a PDF.
- Choose File > Edit Permissions, then do any of the following: - Set a password for opening the PDF: Select Require Password To Open Document. Enter a password, then retype it to verify. 
- Choose which features require a password: Deselect the tickbox to require the owner password for printing or other actions. Leave the tickbox selected to allow changes without the password. 
- Change the owner password: Enter a new owner password, then retype it to verify. 
 
- Click Apply to save your changes.