Protect PDF
Lock your PDF with a password and strong AES-256 encryption, and choose whether people may print, copy or edit it.
How to use — Protect PDF
- 1
Select or drop the PDF you want to protect.
- 2
Type a password and repeat it to confirm.
- 3
Optionally restrict printing, copying and editing.
- 4
Click “Protect PDF” and download the locked file.
Frequently asked questions
How secure is the protection?
Files are encrypted with AES-256, the strongest standard PDF encryption, supported by Adobe Acrobat, Chrome, Edge, Firefox and macOS Preview. A long, unique password is what keeps it safe.
Is my password or file sent anywhere?
No. The encryption happens entirely in your browser. Inopax never sees your PDF or your password, so we cannot recover it for you — keep it somewhere safe.
What do the permission settings do?
They let you block printing, copying text and images, or editing, while still allowing the file to be read. They are enforced by the owner password; note that some PDF apps choose not to respect them.
Can I protect several PDFs at once?
Yes. Add as many PDFs as you like and they will all be protected with the same password and settings, ready to download as a ZIP.
My PDF must open in a very old reader. What should I choose?
Pick AES-128 under Encryption. It works with Acrobat 7 and newer, while AES-256 needs Acrobat X or any modern viewer.