Encrypt PDF — Free Online
Encrypt any PDF file with AES password protection in your browser. No upload to any server, no signup needed. 100% free and completely private.
Encrypt your PDF with industry-standard AES encryption to prevent unauthorized access. Unlike most online tools, the encryption happens entirely in your browser — your password and file data never leave your device.
Drop PDF to password-protect
PDF • Max 200MB
How It Works
Add password protection to any PDF using AES-256 encryption — the industry standard used by banks and governments. The encryption process runs entirely in your browser using WebAssembly, so your PDF and password never leave your device.
Choose a strong password, confirm it, and download the encrypted PDF. Recipients will need the password to open the file. The original formatting, fonts, and images are preserved exactly.
Features
- ✓AES-256 encryption — military-grade security standard
- ✓Password-to-open protection prevents unauthorized access
- ✓Preserves all formatting, fonts, and embedded images
- ✓Handles PDFs up to 200MB
- ✓Zero-knowledge — your password never leaves your device
- ✓Compatible with all PDF readers (Adobe, Chrome, Preview)