Free PDF Password Protect Online
Add password protection to your PDF files with AES encryption. Set open and edit passwords, control permissions.
Supports PDF · up to 100 MB
Encrypting PDF...
✓ PDF protected successfully!
How It Works
- Upload a PDF file using the drop zone above.
- Enter an open password (required) and optionally an owner/edit password.
- Choose encryption strength: 128-bit AES (standard) or 256-bit AES (military grade).
- Select which permissions to allow (printing and copying).
- Click "Protect PDF" to apply encryption.
- Download the password-protected PDF instantly.
Why Protect PDFs?
Password protection ensures that only authorized users can access sensitive documents. Add an open password to restrict who can view the PDF, and an owner password to limit printing, copying, and editing. This is essential for protecting confidential contracts, financial records, medical documents, legal agreements, and proprietary information. Password protection prevents unauthorized distribution and keeps your sensitive data secure.
Password Types Explained
- Open Password · Required to open and view the PDF. Users cannot access the document without this password.
- Owner/Edit Password · Controls permissions like printing, copying text, and editing. Set separately from the open password for additional protection.
Encryption Levels
- 128-bit AES · Standard encryption, widely compatible, fast processing. Suitable for most documents.
- 256-bit AES · Military-grade encryption, maximum security, slightly slower processing. Recommended for highly sensitive documents.
Frequently Asked Questions
What is AES encryption?
AES (Advanced Encryption Standard) is a symmetric encryption algorithm used by governments and organizations worldwide. 128-bit AES is secure for most purposes, while 256-bit AES is military-grade and virtually unbreakable with current technology.
Can I remove a password from a protected PDF?
If you have the owner/edit password, you can remove restrictions. However, if you forget the open password, there is no way to recover it. PDF password recovery is not possible—make sure to save your passwords safely.
Is my PDF secure?
Yes. All processing happens in your browser. Your PDF never leaves your device and is never uploaded to any server. Encryption is applied locally using pdf-lib, which implements the PDF standard encryption methods.
What is the file size limit?
PDFs up to 100 MB can be processed. Processing time depends on file size and encryption level. Larger files with 256-bit encryption may take longer.
What happens if someone bypasses the password?
AES encryption protects the PDF content itself. The password is required to decrypt and view the document. Breaking 256-bit AES encryption with current technology is computationally infeasible.