AES Encrypt/Decrypt

AES is the standard for symmetric encryption: the same password is used to both encrypt and decrypt. This tool derives an encryption key from your password with PBKDF2 and encrypts text with AES-GCM or AES-CBC — all locally in your browser.

How to use it

• Encrypt: enter text and a password, pick a mode (GCM or CBC), and get an encrypted result along with the parameters (salt, IV) needed to decrypt it later.
• Decrypt: paste the encrypted text and the same password to get the original back.
• AES-GCM is the recommended default: it encrypts and verifies data integrity at the same time (authenticated encryption).

Common uses

• Encrypting sensitive text before storing it or sending it over an untrusted channel.
• Checking that an AES encryption implementation matches across different languages or libraries.
• A teaching example for understanding the difference between the GCM and CBC encryption modes.

Things to keep in mind

The IV (initialization vector) must be unique for every encryption performed with the same key — reusing a key+IV pair in GCM completely breaks the encryption's security.

AES-CBC without a separate integrity check (a MAC) is vulnerable to ciphertext-tampering attacks — that's why GCM, which combines encryption and authentication in one mode, is the safer default.