Encrypt a PDF file with AES-256 encryption. The file can only be opened with the password you set using our PDF Unlock tool.
Password-protect your PDF files with encryption. Set an open password to restrict access.
How to Use
- 1 Upload your PDF file
- 2 Adjust settings — encrypt pdf with aes-256 password
- 3 Download the modified PDF
Why Use This Tool
Private & Secure
Your data never leaves your device. Everything is processed right in your browser — nothing is uploaded or stored on any server.
Lightning Fast
No waiting for uploads or server processing. Results appear instantly because all the work happens on your machine.
Free, No Sign-Up
Use this tool as many times as you want. No account required, no email, no limits — just open and go.
Works on Any Device
Use it on your phone, tablet, or computer. No app to install — it runs in any modern web browser.
Frequently Asked Questions
Is PDF Protect free to use?
Yes, PDF Protect is completely free with no usage limits, no account required, and no ads. You can use it as many times as you need.
Is my data safe when using PDF Protect?
Absolutely. PDF Protect runs entirely in your browser. Your files and data are never uploaded to any server — everything is processed locally on your device.
What PDF file size can PDF Protect handle?
Since PDF Protect runs in your browser, it can handle most PDF files. Very large files (100MB+) may be slower depending on your device's memory and processing power.
Do I need to install any software to use PDF Protect?
No installation is needed. PDF Protect works directly in any modern web browser — Chrome, Firefox, Safari, or Edge — on desktop and mobile.