PDF Security

Add Password to PDF

Password-protect your PDF files directly in the browser using strong AES-256 encryption. Set a user and owner password to control who can open, print, or edit your documents. Uses a WebAssembly-compiled engine — your files and passwords never leave your device. No server uploads, no registration.

lockClient-side only
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visibility_offZero uploads
enhanced_encryption

Drop a PDF here or click to browse

Your file never leaves your device

enhanced_encryptionAES-256
cloud_offNo uploads
memoryWASM engine
speedInstant
enhanced_encryption
AES-256 encryption
Industry-standard military-grade protection
speed
WebAssembly engine
Near-native encryption speed in the browser
password
Strong passwords
No restrictions on password length or characters
visibility_off
100% private
Files and passwords never leave your device

How to Add a Password to a PDF

Encrypt any PDF with AES-256 protection — no signup required.

1

Upload your PDF

Drag and drop a PDF onto the upload area, or click to browse your device.

2

Set a password

Enter a strong password and confirm it. The password will be used to encrypt the file.

3

Encrypt

Click 'Encrypt PDF' to apply AES-256 encryption to your document.

4

Download

Download the password-protected PDF instantly. The original file is not modified.

Why Password-Protect a PDF?

Sensitive documents — contracts, financial reports, medical records — should be encrypted before sharing. Password protection ensures only authorized recipients can open the file.

This tool uses AES-256, the encryption standard trusted by governments and banks worldwide. The entire encryption process runs in your browser using a WebAssembly-compiled engine — your files and passwords are never transmitted to any server.

Unlike cloud-based tools, there is no risk of interception or data breach. Your document is encrypted locally and downloaded directly to your device.

Frequently Asked Questions

Are my files uploaded to any server?

No. All processing happens entirely in your browser using WebAssembly. Your files and passwords are never transmitted anywhere — they stay on your device.

What encryption is used?

Your PDF is encrypted with AES-256, the same standard used by governments and financial institutions. This is the strongest encryption level available for PDF documents.

Can I set different user and owner passwords?

This tool sets both the user and owner password to the same value you enter. The user password is required to open the file, and the owner password controls editing and printing permissions.

What happens if I forget my password?

There is no way to recover the password. AES-256 encryption is effectively uncrackable. Make sure to store your password in a safe place.

Is there a file size limit?

No hard limit. The encryption runs in your browser via WebAssembly, so the practical limit depends on your device's available memory. Most files process without issues.

Does encryption change the PDF content?

No. The content, layout, and formatting of your PDF remain exactly the same. Only an encryption layer is added, requiring the password to open the file.

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