AES Decrypt

AES (Advanced Encryption Standard) is a symmetric block cipher standardized by NIST in 2001. It encrypts data in 128-bit blocks using key sizes of 128, 192, or 256 bits. AES-256 is considered quantum-resistant for the foreseeable future.

CBC (Cipher Block Chaining) is recommended for most uses — it requires a random IV and provides good security. ECB (Electronic Codebook) is simpler but less secure because identical plaintext blocks produce identical ciphertext blocks. CTR mode turns AES into a stream cipher and is often the fastest option.

The IV (Initialization Vector) is a random value that ensures the same plaintext encrypted with the same key produces different ciphertext each time. In CBC mode the IV must be 16 bytes (32 hex chars). Leave blank to use a random IV — it will be prepended to the ciphertext output.

Yes. All encryption and decryption happens entirely in your browser using CryptoJS. Nothing is sent to any server. Your plaintext and key never leave your device.