Password Protect a PDF on Mac
Drop your PDF here or click to browse
Supports PDF files up to 10MB
Password-protect your PDF in seconds — no registration, no uploads
You're on a Mac and need to send a confidential PDF — a signed contract, a tax document, or a proposal — with a password so only the recipient can open it. macOS Preview's Export dialog has an Encrypt checkbox, but it offers only a basic open password with no control over what recipients can do with the file: they can still print it, copy text from it, and annotate it freely. To password protect a PDF on Mac with full permission controls and encryption that opens everywhere, you need a different tool — and it doesn't have to cost anything.
Protect PDF on Mac — Free
AES-256 encryption with permission controls. No account, no install — works in Safari, Chrome, Firefox.
Protect PDF Now — Free →What Preview does and doesn't offer
Preview's Encrypt option (File > Export as PDF > Security Options) creates a password-protected PDF using AES-128 encryption. The file will open with a password in most PDF readers. What Preview doesn't support is owner-level permission controls: you can't restrict printing, block text copying, or prevent annotation independently. For contracts where you need to prevent copy-pasting of confidential terms, or sensitive reports you want opened but not redistributed, that gap matters.
Adobe Acrobat Pro adds full permission controls at $19.99/month, Standard at $12.99/month. For occasional use, that's hard to justify. See how Adobe compares to free PDF protection tools for a detailed breakdown of what you get at each price point.
[IMAGE: macOS Preview Export > PDF Security Options dialog showing the basic Open Password field with no separate permission toggles]
How to password protect a PDF on Mac
- Open SignMyPDF Protect in any Mac browser — Safari, Chrome, or Firefox.
- Drag in your PDF or click to browse and upload it.
- Enter a strong password and confirm it.
- Toggle permissions: restrict printing, text copying, and annotating independently.
- Click Protect PDF and download the AES-256 encrypted file.
The protected file opens with your password in any PDF reader on any platform — Windows, Android, iPhone, Chromebook. The whole process takes under a minute with no account required.
Why most Mac PDF tools frustrate you
- Preview lacks permission controls. You can set an open password, but you can't restrict printing, copying, or annotation as separate permissions.
- Adobe Acrobat costs $12.99–$19.99/month — a full PDF suite for what is often a one-off task.
- Most free online tools upload your file to a server. For confidential contracts and sensitive personal data, that's a real privacy concern.
- Smallpdf and iLovePDF cap free-tier tasks at a few documents per day before prompting a paid upgrade.
- Some free tools watermark the protected output — not ideal when you're sending a client a professional document.
If you protect client PDFs regularly as a freelancer, the freelancer guide to protecting client PDF contracts covers a repeatable workflow that stays free.
Why SignMyPDF is different
- Free, no registration, no paywall at download. Protect as many PDFs as you need — no account, no subscription.
- Files processed in browser, never uploaded to servers. Your PDF is encrypted locally on your Mac — nothing is transmitted anywhere.
- AES-256 encryption — a step above Preview's AES-128, and the same standard as Adobe Acrobat Pro. The protected file opens in any PDF reader on any platform.
- Full permission controls. Restrict printing, text copying, and annotation independently, all in one step.
- Works in Safari, Chrome, and Firefox on any macOS version, with no extensions to install.
FAQ
Does Preview's basic password work on Windows and Android? Generally yes — Preview's AES-128 password creates a file that opens in most PDF readers. The limitation is permissions: Preview can't restrict printing or copying, so if those controls matter for your document, you need a tool that supports owner-level encryption.
Is browser-based PDF encryption safe on a Mac? Yes. SignMyPDF encrypts your PDF using the browser's native Web Crypto API — your file is never transmitted to a server. This is more private than Adobe's online tools, which upload documents to Adobe's cloud. If a protected PDF isn't opening correctly on a recipient's device, see why password-protected PDFs sometimes fail to open on certain devices.
What encryption strength does SignMyPDF use? AES-256, the same algorithm used by banks and government agencies for sensitive data — and what Adobe Acrobat Pro uses by default. The strength of a protected PDF is set by the algorithm and your password length, not the tool that applied the encryption.
Password Protect Your PDF on Mac — Free
AES-256, full permission controls, browser-only. Works in Safari, Chrome, Firefox.
Protect PDF Now — Free →