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Password Protect PDF

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.

  • TLS encryption for secure file processing
  • Password-protect your PDF with encryption
  • Quick to protect, near impossible to break
Reliable PDF Password Protection
Prevent unauthorized access to your file’s contents through encrypted password protection. The best method for sharing sensitive content with others securely.
No Data Retention
Smallpdf 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 Linux
As 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 Safety
Some 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 Security
The 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 Cloud
To 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.

How To Password-Protect a PDF Document:

  1. Drag & drop your PDF into the toolbox above.
  2. Enter and repeat the password you'd like to set.
  3. Click “Encrypt PDF” to add the password to the PDF.
  4. Download your password-protected PDF file!
Rate this tool
4.2 / 5 - 13,340 votes