Open Protect PDF and set an opening password. The example protects a four-page PDF using the tool’s default AES-256 encryption.
Choose the file and opening password
Load the PDF and enter the required opening password. The tutorial uses a disposable sample password for verification; choose your own for a real document.
Review encryption and permissions
Keep AES-256 unless you have a specific compatibility requirement. Set an owner password if you need to manage permissions separately, then review printing, copying, editing, assembly, forms and annotations.
Our example keeps high-quality printing allowed and the other permission checkboxes off. Permissions are instructions to compatible readers, so do not treat them as a substitute for controlling access to the file.
Download and test the protected PDF
Choose Start and download. Open the saved file afresh: it should ask for the opening password. Enter the correct password and confirm all four pages appear.
Share the password through an appropriate separate channel when distributing the file, and keep an accessible source copy.
Common questions
Does encryption change the page design?
The example retains the page artwork and four-page count. The visible comparison is shown after successfully opening the encrypted output.
How can I remove the password later?
Use Unlock PDF with the required password and review the unprotected output.
Try it with your document
Review the result, then save the version you need.
