How to protect a PDF with a password
2 min read·23 July 2026
Protecting a PDF with a password prevents others from opening or editing the file freely. What can you set, what does it protect and what does it not, and how do you remove a password afterwards?
Two types of PDF protection
A PDF can have two kinds of passwords: an open password (also called a user password) that you must enter to open the file, and a permissions password (owner password) that restricts editing, printing or copying. The two can be set independently.
How strong is PDF password protection?
PDF security is as strong as the encryption algorithm used and the complexity of the password. Modern PDFs use AES-256, which is extremely strong. Short or simple passwords are vulnerable to brute-force attacks. Use at least 12 characters with numbers and special characters.
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Forgot your password? These are your options
If you forgot the password of your own PDF, you can try to recover it with specialised software. For password-protected PDFs from others you need the password — PDFrust can help remove a password from files you own the rights to.
Remove a password with PDFrust
The Unlock tool on PDFrust removes the password from a PDF so you can open and share the file freely. You enter the current password, the tool decrypts the file locally in your browser and downloads an unlocked version.
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