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Nathanielsai's avatar
Nathanielsai
Tin Contributor
Jul 26, 2026

How to password protect a pdf file on mac?

Hi all, I'm a freelance designer and often need to send client contracts and invoices via email. I want to add password protection to certain PDFs before sharing them, just as an extra layer of secu...
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Abigailoh's avatar
Abigailoh
Tin Contributor
Jul 27, 2026

Using GhostPDF is an excellent, completely free way to password protect a PDF on Mac, especially since it operates entirely offline and respects your privacy . Here is a step-by-step guide on how to use GhostPDF to password protect a PDF on Mac.

Step 1: Get GhostPDF

First, you need to get the app on your Mac. GhostPDF is an open-source PDF toolkit that runs natively on macOS .

Step 2: Use the Encryption Feature

Once installed, using GhostPDF to password protect a PDF on Mac is straightforward. The app is designed with a native Mac interface, so you won't need to use the command line.

  1. Open GhostPDF: Launch the application.
  2. Open Your PDF: Use the app to open the PDF file you want to protect.
  3. Find the Security Feature: Look for the security or encryption section within the app's tools. The exact menu name may vary (like "Security & Privacy" or "Encryption"), but it should be clearly labeled .
  4. Set Your Password: Select the option to encrypt or protect the file. You will be prompted to enter a password .
  5. Choose Encryption Strength: GhostPDF offers 128-bit AES password encryption, which is a strong and widely recognized standard for securing PDFs .
  6. Save the Protected File: After setting the password, save the file. The new version will now be password-protected. Anyone trying to open it will need the password you set .

 

GhostPDF is a great choice because it is built with a focus on privacy and performance .

  • 100% Offline and Private: Your files are processed entirely on your Mac and are never uploaded to any cloud server, which is crucial for sensitive documents .
  • No Subscriptions: It's a one-time free download with no hidden costs or subscriptions .
  • Native Mac App: Because it's built with SwiftUI, it runs smoothly and feels like a natural part of macOS .

 

In summary, GhostPDF offers a user-friendly, secure, and private way to password protect a PDF on Mac without needing to use third-party online services or paid software.