hidekazu-konishi.com

Client-Side AES Encryption Tool - Secure Browser-Based Encryption

First Published: 2025-09-26
Last Updated: 2025-09-26

Free client-side AES encryption tool with instant browser-based security. All encryption and decryption processes are performed entirely within your browser - during the use of this tool, your data never leaves your device or gets uploaded to any server.

⚠️ IMPORTANT DISCLAIMER:

This tool is provided for demonstration purposes only, "AS IS" without any warranties.
We accept NO responsibility for data loss, key loss, or security breaches.
If you lose your encryption key, your data CANNOT be recovered - there is no backdoor or recovery method.
If your key is compromised or leaked, your encrypted data may be exposed.
DO NOT use this tool for critical or sensitive data without understanding the risks.
Always keep secure backups of both your original data and encryption keys.
By using this tool, you accept FULL responsibility for all outcomes and consequences.

Privacy & Security: This tool uses industry-standard AES encryption and operates entirely within your browser using client-side JavaScript. During the encryption and decryption process, no data is transmitted to servers, no files are uploaded online, and all processing happens locally on your device. Even if our website goes offline, the tool will continue to work once loaded. However, security depends entirely on your device security and key management practices. What you do with the encrypted/decrypted files after using this tool is your responsibility.

Encryption Key:

⚠️ Warning: Your key is visible. Ensure no one is watching your screen. Never share or lose this key!

Plain Text:(Decrypt Output)

Encrypted Text:(Encrypt Output)

📁 Select File

File Content (Base64): (Decrypt Output)

Encrypted File Data: (Encrypt Output)

Features:

🔐 AES Encryption: Industry-standard AES encryption algorithm
🖥️ Client-Side Processing: All operations performed locally in your browser
📝 Text & File Support: Encrypt both text content and files
🔑 Custom Keys: Use your own encryption keys or generate secure random keys
📱 Mobile Friendly: Responsive design works on all devices
🔒 No Data Transmission: Your data never leaves your device
💾 File Download: Download encrypted or decrypted files directly

How to Use:

Enter a strong encryption key (minimum 8 characters)
Choose between Text or File mode
For files: Select a file - it will automatically load to the appropriate field
Normal files (*.txt, *.jpg, etc.) → File Content field
Encrypted files (*.enc) → Encrypted File Data field
Click "Encrypt" to secure your data or "Decrypt" to recover it
Use download buttons to save processed files

Security Notes:

Keep your keys safe: Without the correct key, encrypted data cannot be recovered
Use strong passwords: Combine letters, numbers, and special characters
Backup important data: Always maintain secure backups of critical information

Third-Party Libraries

References:
Tech Blog with curated related content
Web Tools Collection

Written by Hidekazu Konishi