PDF Encrypt Tool - Free Online Tool

★★★★½ 4.5 (383 ratings)

🔒 Client-side — Your data never leaves your browser ✅ 100% Free — No signup, no limits ⚡ Instant — No server processing

📋 How to Use

1. Upload PDF — Upload your PDF file (drag & drop or click to select)
2. Enter Password — Set passwords (user password and owner password)
3. Process — Click the encrypt button
4. Download — Download the encrypted PDF file

PDF encryption uses AES-256 encryption algorithm to protect your PDF files. All processing happens locally in your browser — files never leave your device, ensuring complete data security.

The user password (open password) is required to open the PDF. The owner password controls permissions (printing, copying, editing, etc.). Setting an owner password prevents others from modifying the PDF's permission settings.

Yes, using standard PDF encryption algorithms (AES-256 and RC4), encrypted PDFs can be opened in all major PDF readers, including Adobe Acrobat, browser built-in PDF viewers, and more.

This tool supports encrypting any valid PDF file. If the PDF is already encrypted, we recommend decrypting it first before re-encrypting for compatibility. File size under 50MB is recommended for best performance.