AES Encrypt Decrypt — Free Online AES Encryption & Decryption Tool

AES (Advanced Encryption Standard) is the world's most trusted symmetric encryption algorithm. Approved by NIST in 2001 and classified for use with US government Top Secret data, AES-256 provides 256-bit security — more than enough to protect any sensitive information against brute force attacks for the foreseeable future.

This tool implements AES with two modern modes: GCM (Galois/Counter Mode) and CBC (Cipher Block Chaining). AES-GCM is recommended for new applications — it's an authenticated encryption mode that simultaneously encrypts and authenticates your data, making it impossible to tamper with ciphertext without detection. AES-CBC provides encryption without authentication and should be paired with an HMAC for integrity.

Key derivation uses PBKDF2 with 100,000 SHA-256 iterations, converting your password into a cryptographic key. A unique random salt is generated per encryption, preventing pre-computed attacks. All operations use the Web Crypto API — the browser's native cryptographic implementation — with no external libraries required.