How to Use the Protect & Unlock PDF Tool
To secure a document, pick your PDF in the first panel and type the password that will be required to open it. You can optionally set a separate owner password, which is the credential used for changing permissions on the file; if you leave it blank the same password is used for both. Press Encrypt & download and a newly encrypted copy is saved to your device while the original stays untouched.
The second panel does the opposite. Choose a locked PDF, enter the password you already use to open it, and the tool decrypts the document and rebuilds it without any password so it can be read, printed or edited freely. Both operations run entirely inside your browser tab, which means your password is never typed into a remote form and your confidential document is never uploaded anywhere.