Encrypt and decrypt text using AES-256-GCM (secure), ROT13, or Caesar cipher. Password-based encryption with the Web Crypto API. All processing happens entirely in your browser—your data never leaves your device.
Industry-standard encryption using AES-256 in Galois/Counter Mode with password-based key derivation (PBKDF2). Provides both confidentiality and authenticity.
Choose between AES-256-GCM for security, ROT13 for simple obfuscation, or Caesar cipher with customizable shift for educational purposes.
Real-time password strength indicator helps you choose strong passwords for AES encryption. Visual feedback shows weak, medium, or strong ratings.
All encryption happens in your browser using the Web Crypto API. Your text and password never leave your device. No server communication.
Encryption is the process of converting readable text (plaintext) into an unreadable format (ciphertext) using a mathematical algorithm and a key or password. Only someone with the correct key can decrypt the ciphertext back to plaintext. Encryption is fundamental to modern digital security, protecting everything from passwords and financial data to private messages and sensitive documents. This tool provides three encryption methods, each suited for different purposes.
AES (Advanced Encryption Standard) with a 256-bit key in Galois/Counter Mode is the gold standard for encryption. It's used by governments, banks, and security professionals worldwide. AES-256-GCM provides authenticated encryption, meaning it not only encrypts your data but also verifies that it hasn't been tampered with. This tool uses the Web Crypto API to perform AES-256-GCM encryption with PBKDF2 (Password-Based Key Derivation Function 2) to derive a strong encryption key from your password. A random salt and initialization vector (IV) are generated for each encryption, ensuring the same plaintext produces different ciphertext each time. The encrypted output is Base64-encoded for easy copying and sharing.
ROT13 and Caesar cipher are simple substitution ciphers from classical cryptography. ROT13 rotates each letter by 13 positions in the alphabet (A becomes N, B becomes O, etc.). Because there are 26 letters, applying ROT13 twice returns the original text, making encryption and decryption the same operation. Caesar cipher is similar but allows you to choose the shift amount (1-25). Julius Caesar famously used a shift of 3 to encode military messages. These ciphers are not secure—they can be broken in seconds—but they're useful for simple obfuscation, educational purposes, or hiding spoilers. Never use ROT13 or Caesar cipher to protect sensitive data.
For AES-256 encryption, your password's strength is critical. A weak password can be cracked through brute-force or dictionary attacks, rendering even the strongest encryption useless. A strong password should be at least 12 characters long, include uppercase and lowercase letters, numbers, and special characters, and avoid common words or patterns. Passphrases—long phrases made of random words—are both strong and memorable. This tool includes a password strength indicator to help you choose an appropriate password. For maximum security, consider using a password manager to generate and store truly random passwords.
Check out our other free security and encoding tools. Generate passwords, encode Base64, hash text, and more.
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