Password-protect a PDF with AES-256 encryption and print/edit permissions.
Loads its engine on first use, so there's no offline download — but it still runs privately in your browser, nothing uploaded.
Drop a PDF here, or click to choose
The open password is required to view the PDF. The owner password controls permissions; if empty, the open password is used for both.
About this tool
Protect PDF is a free, in-browser tool that encrypts a PDF with a password using AES-256, the strongest encryption the PDF standard supports. Everything runs on a WebAssembly build of qpdf inside your browser, so your file and your passwords never leave your device — nothing is uploaded anywhere.
You set an open password that anyone will need to view the document, and optionally a separate owner password that controls the security settings. Checkboxes let you decide whether readers may print the document and whether they may modify it; those permissions are written into the encryption so compliant PDF viewers enforce them.
A protected PDF is a sensible extra layer when emailing contracts, payslips, medical records or anything personal. Keep the password safe and share it through a different channel than the file itself — with AES-256 there is no way to recover the contents if the password is lost.
Frequently asked questions
How strong is the encryption?
The file is encrypted with AES-256 (PDF 2.0 / security revision 6), the strongest scheme in the PDF specification. Without the password the contents cannot be recovered, so store it safely.
What is the difference between the open and owner passwords?
The open (user) password is required to view the document. The owner password controls permissions and security settings. If you leave the owner field empty, the open password is used for both.
Are the permission checkboxes always enforced?
Compliant PDF viewers honor them, but once someone knows the open password enforcement ultimately depends on their software. Treat permissions as a strong signal, and the password itself as the real protection.
Is my file or password uploaded?
No. Encryption happens in a WebAssembly build of qpdf running locally in your browser — your PDF and both passwords never leave your device.