How to protect a PDF with a password
2 min read·24 July 2026
You want a PDF to be available only to the right person. Adding a password to a PDF is the most direct way. This article explains how it works and what options you have.
Two types of protection
There are two kinds of PDF protection: an open password (the PDF only opens after entering the password) and a permissions password (the PDF opens but printing, copying or editing is blocked). Many free online tools only offer permissions passwords; an open password requires specific software such as Adobe Acrobat or LibreOffice.
Free options for protection
LibreOffice Draw is free and can save PDFs with an open password: open the PDF, choose Export as PDF and enter a password under Security. Adobe Acrobat Reader can only read PDFs, not protect them; for that you need Acrobat Pro.
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Removing protection
Are you the owner of the PDF and want to remove the protection? Use the "Unlock PDF" tool on PDFrust. This removes owner restrictions (printing, copying, editing). A PDF that requires a password to open can only be unlocked if you know the password.
Choosing a strong password
PDF passwords are sometimes attacked with dictionary tools. Choose a password of at least 12 characters with letters, numbers and symbols. A passphrase of four random words is also strong and easier to remember.
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