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Protect PDF

PDFFree · Private

Add a password to your PDF to prevent unauthorized access. Set open and permissions passwords. Everything runs in your browser — your PDF is never uploaded.

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Drop a PDF here or click to browse

Your PDF is encrypted in your browser using 128-bit AES. The file and password are never sent anywhere.

Open password vs owner password

The open password (user password) is required to view the PDF at all. The owner password controls permissions — printing, copying text, and editing. If you only want to restrict editing but not viewing, set only the owner password.

Encryption details

This tool uses 128-bit AES encryption via the pdf-lib library. The PDF and password are processed entirely in your browser — nothing is transmitted over the network.

Frequently Asked Questions

How do I password protect a PDF?
Upload your PDF, enter a password, and click Protect. The encrypted PDF downloads immediately — it will require the password to open.
What is the difference between user and owner password?
The user password is required to open the PDF. The owner password controls permissions like printing and copying. You can set either or both.
Is the encryption strong?
The tool uses 128-bit AES encryption via the pdf-lib library, which is sufficient for most document protection purposes.

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