"This PDF is protected" can mean two very different things. One kind stops anyone opening the file without a password. The other lets everyone open and read it but blocks printing, copying or editing. Knowing which one you have tells you what you can do about it.
1. Opening password
When you open the file, you are asked for a password before you see anything. The content is encrypted: without the password it is unreadable, not just hidden.
- Banks and companies often send statements and payslips this way, with a password such as your date of birth or ID number.
- If you know the password, you can remove it so you do not have to type it every time: use Unlock PDF and choose Opening password.
- If you do not know it, there is no honest shortcut. Modern PDF encryption (AES-256) cannot be guessed in any reasonable time unless the password is very short. Ask the sender.
2. Restrictions (permissions)
The file opens normally, but printing is greyed out, or you cannot select and copy text, or editing is blocked. These are permissions set by the person who made the file.
- The content is readable by anyone who opens it, so the restrictions are an instruction to PDF programs rather than strong protection.
- If you are allowed to use the document, you can remove them without any password: open Unlock PDF. It detects the restrictions and selects Restrictions only for you.
- Respect the owner's wishes. Restrictions are often there for copyright or confidentiality reasons. Only remove them from documents you are entitled to use that way.
Adding a password to your own PDF
Before you email a document with personal or financial details, you can lock it with Protect PDF. It uses AES-256 encryption, the strongest standard PDF readers support.
- Send the password separately. If the password is in the same email as the file, the protection is pointless. Send it by text message or tell the person by phone.
- Use a real password, at least 10 characters, not just a name or a date.
- Keep a copy. If you forget the password, nobody can recover the file, including us.
Quick reference
- Asks for a password to open, and you know it: Unlock PDF, Opening password.
- Opens fine but will not print or copy: Unlock PDF, Restrictions only.
- You want to lock your own file: Protect PDF.