How to password-protect a PDF
Updated October 7, 2026
A password-protected PDF only opens for people who know the password, even if the file ends up in someone else’s hands, whether by email, on a USB drive or in the cloud. With Protect PDF, the PDF is encrypted on your device and neither the file nor the password is sent anywhere.
Protecting a PDF, step by step
- Open Protect PDF and drag the PDF into the workspace. With several PDFs, they all get the same password (any that already have a password to open are skipped: protect those one at a time).
- Type the “Password to open” and confirm it.
- Choose what people can do once the PDF is open: “Allow printing”, “Allow copying text and images” and “Allow editing”.
- Click “Protect PDF” and download the result. The original stays as it was. If the PDF has a digital signature (for example, from a national ID card), it will no longer be valid in the protected PDF: MovaDoc warns you first.
How to choose a good password
The PDF’s security depends mostly on the password. Choose a long one that’s hard to guess: a phrase of four or five unrelated words is stronger, and easier to remember, than a single word with a number at the end. Don’t use birth dates, family members’ names or passwords you already use elsewhere.
Send the password through a different channel from the one you used for the file: for example, the PDF by email and the password in a text message or over the phone. To store it, use a password manager.
AES-256 or AES-128
By default, MovaDoc uses AES-256, the strongest password protection in the PDF standard, which current PDF readers can open. AES-128 is only for very old readers. Either way, the PDF’s text, images and metadata are encrypted.
Permissions and the owner password
The permissions (printing, copying, editing) show what the author allows. Most PDF readers respect them, but some programs ignore them: what really protects the content is the password to open.
If you want to be able to change the permissions later, fill in “Owner password (optional)”: it must be different from the password to open. Without it, to change the permissions you have to protect the original PDF again.
If you forget the password
There’s no way to recover it: MovaDoc doesn’t store it, in the browser or anywhere else. Keep the password somewhere safe.
To remove the protection from a PDF whose password you know (the password to open or the owner password), use Unlock PDF: it creates a copy without a password. It doesn’t guess or crack passwords, and you should only use it on files you own or are allowed to open.
What to check at the end
- Open the protected PDF (ideally in another reader or on another device): does it ask for the password?
- Does the password work? Try it before you send the file.
- Have you deleted the unprotected copy, or put it somewhere safe? The original stays as it was, so it’s still unprotected in your folder.
- Before protecting it, did you remove anything the recipient doesn’t need to see? The password protects against third parties, not against the person who receives it: redact what mustn’t be read.