How to Encrypt a PDF on a Mac

How to Encrypt a PDF on a Mac

PDFs have become a “go-to” file format for sharing and preserving information. If you’re like me - and many of my clients - some of your PDFs contain sensitive information of either a personal or financial nature (e.g. tax returns back to your accountant). Take a step to guard those sensitive PDFs by encrypting them. This is a good idea if you have your sensitive files on a laptop or would like to share them with others via email or some other file sharing system such as Dropbox, SugarSync, etc.

Using Apple’s Preview on your Mac, it’s pretty simple to encrypt your PDF:

Open the PDF you wish to create in Preview and choose File > Duplicate.

When you go to close that duplicate file using either the red dot in the upper left corner, File > Close, or , you’ll be prompted with a Save dialog box.

Assign your PDF a file name in the “Save As” line and determine where you’d like the file saved in the “Where” line. Then continue down the screen and you’ll notice a check box to “Encrypt” the file.

Preview - Encrypt1


Check that “Encrypt” box. When you do, two password fields will appear. Enter the password you would like to be required to open the file in each of those two password fields. Note that you’ll need to remember this password.
If you cannot, you will not be able to open your encrypted PDF in the future.

Preview - Encrypt2


Click “Save.” As soon as your file is saved, your file is encrypted. You’ll notice that the icon for your PDF now has a lock on it.

Preview - Encrypt3


If you’re planning to transmit your encrypted PDF via email or a file sharing platform like Dropbox, remember to share your file or file location and the password for your file separately. In other words, don’t email the encrypted document with its password in the same email. Consider calling the recipient and giving him/her the password verbally.

Please note that these steps assume you’re running Mavericks on your Mac. If you’re running an older version of Mac OS, the steps are slightly different. Interested in how to encrypt PDFs for those older versions? Send us an email with your OS and I’ll reply with the details!