How to use Protect PDF — Add a Password to a PDF Online Free (AES-256)
- 1Upload your PDF or document.
- 2Choose the options for this tool.
- 3Download the result — processed on our server and deleted immediately after.
About Protect PDF
Sending a contract, a medical report or a payslip? A password keeps it private even if the email is forwarded. Anyone can add a password in seconds here; the document is encrypted with AES-256 and only the holder of the password can open it.
Frequently asked questions
How strong is the encryption?
AES-256, the current PDF 2.0 standard. Without the password the content cannot be read.
What is the owner password for?
It lets you change permissions or remove the protection later. If you leave it blank, the open password is used.
Can the password be recovered?
No. There is no back door — keep it somewhere safe.