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Free Web Tool

Protect PDF

Add a password to your PDF and control who can open, print, or copy it. Encryption runs in your browser — nothing is uploaded.

Frequently Asked Questions

Are my files or passwords sent to a server?
No. Encryption happens entirely in your browser. Your file and password never leave your device.
What permissions can I restrict?
You can control: printing, copying text/images, modifying the document, annotating, and filling forms. Disable any combination to restrict what recipients can do.
Can I remove the password later?
Yes, use our Unlock PDF tool. You will need to know the password to remove it.
What is the difference between user and owner password?
The user password is required to open the PDF. The owner password controls who can change permissions, print, or copy content. If you only set a user password, it will also serve as the owner password.
How strong is the encryption?
pdf-lib uses AES encryption. The security depends on your password strength — use a long, unique password for maximum protection.

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