RapidHow to Password Protect a PDF on Mac — Free, No Upload
Two free ways to put a password on a PDF on a Mac: a browser tool with AES-256, and Preview’s Permissions option.
⚠️ Always use a copy of your document, never the original. Keep your original file safe.
How to password protect a PDF on Mac has two free answers. The simplest is our free Password Protect PDF tool: open it in Safari or Chrome, choose the PDF, type a password and click Encrypt & Download PDF. It locks the file with AES-256 encryption in your browser, so nothing is installed and your PDF and password stay on your Mac. The built-in option is Preview: choose File > Export, click Permissions and turn on Require Password To Open Document.
This guide covers only the Mac. For other devices, see the main guide: how to password protect a PDF.
Method 1: Password Protect PDF in Your Browser (Simplest)
This works in Safari, Chrome, Firefox and Edge on any Mac. Your PDF and your password are handled by your browser on your own Mac. They are not sent to a server.
- Open rapidtools.online/password-protect-pdf. No account is needed.
- Drag your PDF into the box, or click the box and choose the file in Finder.⚠️ Always use a copy of your document, never the original. Keep your original file safe.
- Type an Open Password. Anyone who opens the PDF will need it.
- If you want, type a Permissions Password and tick Prevent Printing, Prevent Copying Text or Prevent Editing. Restrictions only work when a permissions password is set.
- Click Encrypt & Download PDF. The locked file downloads with “-protected” added to the name.
Method 2: Preview (Built In)
Preview comes with every Mac and can add a password when you export a PDF. These steps follow Apple’s Preview guide.
- Open the PDF in Preview.
- Choose File > Export.
- Click Permissions.
- Select Require Password To Open Document, type a password, then type it again to check it.
- To control printing and changes, type an Owner Password and choose which actions are allowed without it.
- Click Apply, then click Save.
Preview uses older 128-bit encryption, which is weaker than the AES-256 our tool uses but fine for everyday files. To change the password settings of a PDF that is already protected, Apple says to choose File > Edit Permissions. Source: Apple: Password-protect a PDF in Preview on Mac.
Which Method Should You Use?
| Browser tool | Preview | |
|---|---|---|
| Install | None | None (built in) |
| Encryption | AES-256 | Older 128-bit |
| Open password | Yes | Yes |
| Print, copy and edit limits | Yes, with a permissions password | Yes, with an owner password |
| File leaves your Mac | No | No |
Need to remove a password you know? See the free Remove PDF Password tool. Sharing a document with private details? Learn how to redact a PDF on Mac first.
Frequently Asked Questions
How do I password protect a PDF on a Mac for free?
Open rapidtools.online/password-protect-pdf in Safari or Chrome, choose the PDF, type an open password and click Encrypt & Download PDF. You can also use Preview: choose File > Export, click Permissions, select Require Password To Open Document, type a password, then click Apply and Save.
What encryption does the browser tool use?
AES-256, the strongest encryption the PDF standard supports. Preview uses older 128-bit encryption, which is weaker but fine for everyday files.
What is the difference between an open password and a permissions password?
An open password is needed to open the PDF at all. A permissions password, called an owner password in Preview, controls things like printing, copying text and editing. Restrictions only work when that password is set.
What if I forget the password?
There is no way to open the file without the open password, so write it down somewhere safe and keep your unlocked original until you have checked the new file.
Is my PDF uploaded when I use the browser tool?
No. Your PDF and your password are handled by your browser on your own Mac and are never sent to a server.