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.

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 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).