About Protect PDF

This tool takes one password and encrypts your PDF with it using 256-bit AES — the same encryption standard used by financial institutions and government agencies. That single password does two jobs at once: it's required to open the file at all, and once someone opens it, a fixed set of restrictions kicks in automatically. There's currently no separate "owner-only" password option here — every protected file requires the password just to view it, not only to edit it.

The restrictions themselves aren't configurable per file: printing stays fully allowed, while copying text, editing, filling in forms, and extracting or reassembling pages are always blocked. That fixed combination covers the most common reason people protect a PDF — stopping casual copying and tampering — without needing a settings panel full of checkboxes.

Key Features

• 256-bit AES encryption via qpdf, with an automatic fallback if qpdf is unavailable
• One password required both to open the file and to trigger the restriction set
• Printing stays allowed; copying, editing, form filling, and page extraction are always blocked once protected
• Compatible with all standard PDF readers, including Adobe Acrobat and browser-based viewers
• Original document quality, layout, and content preserved exactly — only encryption is added