GuidesHow to Password Protect a PDF (Windows, Mac, Linux, Online) — 2026 Guide
You can password protect a PDF in under a minute on Windows, Mac, and Linux — without paid software. The trick most guides skip: the encryption level dropdown. Adobe Acrobat, macOS Preview, Microsoft Word, and qpdf all support AES-256, but you have to know where to look. Here's the full walkthrough.
Surya Prakash 