AES Encrypt / Decrypt
Encrypt and decrypt data with AES-128, AES-192, or AES-256 in CBC, CFB, CTR, OFB, and ECB modes
What is AES encryption?
AES (Advanced Encryption Standard) is the global standard for symmetric encryption, adopted by the U.S. government and used worldwide to protect sensitive data. It encrypts data in 128-bit blocks using key lengths of 128, 192, or 256 bits. AES is fast, highly secure, and implemented in hardware on virtually every modern processor.
This tool supports all five standard modes of operation — CBC, CFB, CTR, OFB, and ECB — and both PBKDF2 and EvpKDF key derivation from passwords. AES-256-CBC is recommended for all new applications requiring strong encryption.
How to use AES Encrypt / Decrypt
Enter your data and key
Type or paste the plaintext to encrypt (or ciphertext to decrypt) and enter your encryption key or password.
Configure AES settings
Select key size (128, 192, or 256 bits), mode of operation (CBC is recommended), and key derivation options.
Click Encrypt or Decrypt
The result appears instantly in your browser.
Copy the output
Click Copy to copy the ciphertext or decrypted plaintext.
Frequently asked questions
What is the difference between AES-128, AES-192, and AES-256?
The numbers refer to the key length in bits. AES-256 uses a 256-bit key and is the strongest, suitable for the highest security requirements. AES-128 is faster and still provides strong security for most applications. AES-192 is rarely used in practice.
Which AES mode should I use?
CBC (Cipher Block Chaining) is recommended for general use. CTR (Counter) mode is preferred for streaming data. ECB (Electronic Codebook) should be avoided — it does not hide patterns in the data and is considered insecure for most uses.
What is an IV (initialization vector)?
An IV is a random value combined with the key to ensure that identical plaintexts produce different ciphertexts. It does not need to be secret but must be unique for each encryption operation. CBC, CFB, CTR, and OFB modes all require an IV.
Is my data sent to a server?
No. All AES encryption and decryption runs in your browser using the CryptoJS library. Your data and keys are never transmitted over the network.