Apple Support article on how to enable password protection for the PDF in Preview. Apr 16, 2023 — If you choose to create a password-protected PDF, Then select Apple > Encrypt PDF… from the Tools section. What to do to decrypt the password-protected PDF The password can be decrypted using your favorite PDF viewer. How to remove password from a PDF file on Mac If the password has been unlocked, then go to the password-protected PDF file using Previewed How to remove password from PDF on Mac Using Adobe Acrobat Open your password-protected PDF file. Do not save the file. Choose File > Open… from the main menu and select the password-protected PDF file. If you don't want to decrypt the PDF with Preview, then click “Open Previewed PDF” from the main menu and choose the password-protected PDF file to open. Other ways to remove password from PDF files on Mac To decrypt the password from PDF with Adobe Acrobat you have to manually extract the password using an application such as Microsoft Silver light Reader: Extract the password using Adobe Acrobat. Then, open the decrypted PDF file by right-clicking on it and choose Open. Use Acrobat Reader to decrypt PDF password. First download the .ACM file to the computer. After unpacking, choose Acrobat Reader > Acrobat Editor > Encrypt Page. To enable password protection for a password-protected PDF in Acrobat on Mac you need to go to Adobe Acrobat > Settings > Protected Publications > PDF Settings > Password Protection. Make sure that Encrypt PDF is selected, and then click Save. You can choose to keep the encryption without the password, if the file is not encrypted. A password has been reset If the password was inadvertently reset, and you can't decrypt it, then it's possible that Adobe Acrobat has been used to download your password-protected PDF file. In that case, you can enter the email address and password you've used to open the PDF file. Adobe recommends using a real email address with a valid password, since the password reset link you've been sent will be able to be opened only by an Adobe ID account.