How to password protect a PDF for free

1 min read·25 July 2026

Protecting a PDF with a password prevents unauthorised people from opening or editing the file. With PDFrust you set an open password and/or editing restrictions directly in your browser — no software or account needed.

Two types of protection

There are two types of PDF protection: a password to open the file (user password) and a password to prevent editing, copying, or printing (owner password). PDFrust supports both.

How to protect a PDF

Upload your PDF to the protection tool. Enter a password in "Password to open" and/or "Edit protection". Click protect and download the secured PDF. The original remains unchanged.

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Choosing a strong password

Use a password of at least 12 characters with letters, numbers, and symbols. PDF protection uses AES-128 or AES-256 encryption. Store the password safely: if you forget it, there is no recovery option.

Remove protection

Do you still know the password? You can also remove the protection via PDFrust. Upload the protected PDF, enter the password, and download the unprotected version.