How to protect a PDF with a password

Encrypt a PDF with a password you choose, without installing software.

Updated Aug 20, 2026

To protect a PDF, add an opening password: only someone who knows it can open it. You choose the key and it is not stored anywhere.

Protect the PDF step by step

Upload the PDFOpen the protect PDF tool and select the unencrypted document.
Choose a passwordType a key you can remember; it is used to encrypt the file.
Download the protected PDFSave it; opening it will ask for the password you chose.

Quick answers

No. The key is used to encrypt the file and is not stored. If you forget it, there is no way to recover it.

It cannot be recovered or “broken”. Store it somewhere safe before you share the PDF.

Not in this step. Unlock it first if you know the key, or start from an unencrypted file.