Add real AES-128 password protection to your PDF — free, browser-based, and 100% private. The output requires your password to open in any PDF viewer.
Real AES-128 encryption: This tool encrypts your PDF using the PDF standard security handler — the same method Adobe Acrobat uses. Any PDF viewer (Adobe Reader, Chrome, Preview, Foxit) will ask for the password before opening.
Upload the PDF you want to protect.
Enter and confirm a strong password.
Download your encrypted PDF — requires password to open.
Yes, 100% free with no sign-up and no usage limits.
Yes. Everything is processed locally in your browser using pdf-lib. Your PDF and password are never sent to any server.
AES-128 encryption using the PDF Standard Security Handler — the same encryption method used by Adobe Acrobat's password protection. The output file will ask for the password before opening in any PDF viewer (Adobe Reader, Chrome, Preview, Foxit, Edge).
No — you must first remove the existing password using our Unlock PDF tool, then re-protect it with a new password.
Yes! Fully responsive on iOS and Android browsers.