No file size limits, no ad watermarks - A simple and secure web app to encrypt your PDF files with strong AES 128-bit encryption for free.
Reliable PDF Password ProtectionPrevent unauthorized access to your file’s contents through encrypted password protection. The best method for sharing sensitive content with others securely.
No Data RetentionSmallpdf doesn't save any passwords and files are deleted permanently after one hour. All data transfers are handles through TLS encryption to ensure the safety of your data.
On Mac, Windows, and LinuxAs a web application, Smallpdf can be accessed using a Mac, Windows, or Linux machine, or even a mobile device. Just open your browser to protect your PDF!
Secure Encryption for Maximum SafetySome PDF passwords can be hacked easily. With our AES 128-bit encryption, it would take thousands of years to crack your password with a regular computer.
Password Strength for Added SecurityThe more complex your password, the safer your file. We recommend using a non-dictionary word of at least 7 characters with numbers, capital letters, and symbols.
Password-Protection in the CloudTo use Smallpdf, you don't need any software. You can encrypt your PDF with a password by simply uploading it, choosing a password, and then downloading the result.
You can use the Smallpdf Protect PDF tool to encrypt your PDFs with unbreakable passwords online—for free.
How To Protect PDF How to Create a Strong Password the Old-School WayCreating a strong, secured and memorable password is not difficult. Follow our guide to do so at the snap of a finger.