Password Protect a PDF Online

Open password + permission controls (print/copy/edit), AES-256 standard encryption

Before sending a payslip, contract, or medical report, adding a password is the most basic protection. This free tool supports both password types: an open password (recipients must enter it to view) and an owner password with granular permissions (viewable, but printing, copying, or editing blocked as you choose).

Encryption uses the PDF-standard AES-256 algorithm via the qpdf WASM engine in your browser - the file and passwords never leave your machine. Protection is at the file level: every reader on every platform will ask for the password.

Tip: send the password through a different channel than the file (e.g., file by email, password by text message).

How to use

Click "Encrypt / Decrypt" (the Encrypt tab is default)
Select the PDF to protect
Set an open password, or an owner password with blocked actions
Download the encrypted PDF

FAQ

How strong is the encryption?

PDF 2.0-standard AES-256. With a long random password, brute force is impractical; weak passwords like 123456 remain easy dictionary targets.

Open password vs owner password?

Open password: the document cannot be viewed at all without it. Owner password: viewing is allowed but printing/copying/editing are blocked per your settings. Both can be set together.

What if I forget the password?

There is no backdoor. Use a password manager - a lost open password means the content is permanently inaccessible.

Do encrypted PDFs work on phones?

Yes. iOS/Android system viewers and all mainstream apps support standard encrypted PDFs - just enter the password.