Can I set separate open and owner passwords in Preview?

No — Preview only supports a single open password. For separate user/owner passwords (to control printing, copying, and editing independently of the open password), use Protect PDF.

Does the password get sent to your servers when I use PDFWix on a Mac?

No. The encryption runs entirely in your browser using JavaScript and WebAssembly. Your PDF and password never leave your Mac — verify in Safari Web Inspector or Chrome DevTools > Network tab during the encrypt step.

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How to Password-Protect a PDF on Mac

A simple step-by-step guide to password-protect a pdf on Mac using PDFWix's free online tools.

How to Password-Protect a PDF on Mac

Password-protect a PDF on macOS using Preview's Export with password, or PDFWix in Safari. Free, browser-based AES-256, no install, no signup. Get started.

Tip: owner vs user passwords

PDFWix Protect lets you set two passwords on the same file. The 'user' password is required to open the document. The optional 'owner' password controls what the opened document can do — print, copy text, edit, fill forms — even after the user opens it. Set both for sensitive contracts: a strong user password keeps the file private in transit, and a separate owner password prevents the recipient from copy-pasting or editing the contents after opening. Both passwords use AES-256 and never leave your device — encryption runs entirely in your browser via a WebAssembly build of qpdf.

How it works

Open the PDF in Preview — Double-click the PDF in Finder so it opens in Apple Preview.
Open Export dialog — File > Export… (not Export as PDF — full Export).
Show details — Click 'Show Details' to expand the dialog if collapsed.
Encrypt with a password — Tick the 'Encrypt' checkbox and type a strong password (verify it in the second field).
Save the encrypted PDF — Click Save — the resulting PDF is AES-128 encrypted and requires the password to open.

Frequently asked questions

Does Apple Preview really encrypt PDFs natively?

Yes. File > Export > Show Details > tick 'Encrypt' applies real PDF-level AES-128 encryption (PDF 1.6 standard). It's not a wrapper or a zip — it's a fully encrypted PDF that requires the password to open in any PDF viewer.

What encryption strength does Preview use?

AES-128 (PDF 1.6 specification). Strong enough for almost all personal and professional use. For regulated industries that mandate AES-256 specifically, use Protect PDF which applies AES-256 (PDF 1.7 Extension Level 8).

Does Preview's password protection work on macOS Sequoia (15)?

Yes. The Encrypt checkbox in File > Export > Show Details works identically on Big Sur (11), Monterey (12), Ventura (13), Sonoma (14), and Sequoia (15).