Protect PDF
Lock a PDF behind an open password so it cannot be viewed without it.
Drop a PDF here
or browse your device · paste with Ctrl+V
One PDF at a time for this tool. Nothing is uploaded — the document is edited in memory.
PDF
About this tool
Encrypts the file with AES-256 (PDF 2.0). Anyone opening it in Acrobat, Preview or a modern browser will be asked for the password. The encryption runs entirely in this tab — the document is never uploaded.