PDFs and conversion

How to password-protect a PDF on a Mac

Updated 25 October 2026 · 3 min read

Preview can lock a PDF with a password in a few clicks. Here is how, what the owner password actually controls, and how Orrel adds or removes a password while keeping the original file.

A password on a PDF is the simplest way to send a payslip, a tax return or an ID scan by email without the contents being readable to anyone who gets hold of the message. macOS can do it with Preview.

Add a password in Preview

1. Open the PDF in Preview.
2. Choose File › Export. To keep an unprotected original, type a new name for the copy.
3. Click Permissions.
4. Select Require Password To Open Document, then enter and verify the password.
5. In the Owner Password section, enter and verify an owner password. It can be the same as the opening password or different.
6. Click Apply, then Save.

To change the passwords or permissions later, open the PDF, choose File › Edit Permissions, make your changes and click Apply.

What the permissions do

Below the opening password are checkboxes for printing, copying text and graphics, inserting or removing pages, and annotating. These are restrictions the PDF asks reading apps to follow. Most do, but they are not encryption in the way the opening password is, and a determined person with the right tool can ignore them. If the content matters, rely on the opening password.

Choosing a password

• Long beats clever. Three or four unrelated words are stronger than a short password with symbols.
• Send it separately. A password in the same email as the PDF protects nothing.
• Keep a copy. There is no reset. Store it in the Passwords app or your password manager.

Removing a password

If you know the password and want an unprotected copy, for example to merge the PDF with others, open it with the password and export a copy. Check the result opens without asking before you delete anything.

How Orrel does it

In Orrel's PDF workspace, select the pages you want and choose to save a protected copy. Enter a password and Orrel writes a new PDF beside the original that needs the password to open. The original is not changed, so you keep an unprotected copy for yourself.

• Protect after merging. Merge several files, reorder the pages, then save the result with a password in one pass.
• Open protected PDFs. Drop in a locked PDF, enter its password, and you can include its pages in a merge or save a copy without a password.
• Ask an assistant. With Orrel connected to Claude or Cursor, "password-protect the payslip in Downloads" runs on your Mac. The assistant asks before it writes the file.

Where Orrel stops

Orrel cannot open a PDF without its password and offers no way to recover a forgotten one. It sets a password to open the file; it does not offer the individual permission checkboxes that Preview's Permissions sheet does, so use Preview if you need, say, printing allowed but copying blocked. A password protects the file, not the email it travels in, so send the password separately.