Protect PDF, instantly.
Add password protection to your PDF. Browser-based, no upload.
Drop your PDF here
or browse files · max 25 MB
Understanding PDF password types
User Password (Open Password)
Required to open and view the PDF. Without it, the document is completely inaccessible. Best for protecting payslips, contracts, invoices, and personal documents you're sharing via email.
Owner Password (Permissions Password)
Controls what users can do with the PDF — like printing, copying text, or editing. The PDF can still be opened without it, but certain actions are restricted. Useful for public documents where you want to prevent copying.
Processed entirely in your browser
Protection is applied using pdf-lib running in your browser. No file is uploaded to any server. The protected PDF downloads directly to your device.
Frequently Asked Questions
What is the difference between user and owner password?
The user password (open password) is required to open and view the PDF. The owner password controls permissions like printing and copying. You can set one or both. For most use cases (protecting payslips, invoices), just the user password is sufficient.
Is this 100% secure encryption?
pdf-lib uses 128-bit AES RC4 encryption — the standard PDF encryption supported by most desktop PDF editors, browsers, and readers. It is sufficient for protecting personal documents. For very sensitive data, consider additional security measures.
Does the file get uploaded to protect it?
No. Protection is applied entirely in your browser using pdf-lib JavaScript library. Your file never leaves your device.
What happens if I forget the password?
You can use our Unlock PDF tool to remove it — but you will need the password for that too. Always save your password securely.
What is the difference between user password and owner password?
A user password (open password) prevents anyone from opening the PDF without the password. An owner password sets restrictions like preventing printing, editing, or copying while still allowing the PDF to be opened. This tool sets a user password for maximum protection.
Key Terms
PDF Encryption
The process of scrambling PDF content so it can only be read with the correct password. Uses AES-128 or AES-256 encryption standards.
User Password
Required to open and view the PDF. Without it, the document is completely inaccessible.
Owner Password
Controls permissions like printing, editing, and copying. The PDF can still be opened without it, but certain actions are restricted.