AES Encrypt / Decrypt

What is AES Encrypt / Decrypt?

AES is the most widely used symmetric cipher — API payload encryption and database field encryption are almost always AES. The classic integration pain is "the ciphertext does not match": any mismatch in mode, padding, IV or key length breaks decryption. This tool supports CBC and ECB modes, Pkcs7 and ZeroPadding, and Base64 or Hex output. All computation runs in your browser; keys never cross the network.

How to Use

1. Choose encrypt or decrypt, then enter the content and key
2. Select mode / padding / output encoding (matching the other system)
3. View the result and copy it

FAQ

Should I choose CBC or ECB?

CBC is more secure (identical plaintext yields different ciphertext each time) and is the recommended default; ECB is only for compatibility with legacy systems — do not use it in new ones.

What are the key length requirements?

AES supports 16/24/32-byte keys (AES-128/192/256). This tool takes the key as UTF-8 bytes and, in CBC mode, uses the first 16 bytes as the IV — a convention shared by most backends.

Why is the decrypted output garbled?

Check item by item: key, mode, padding and ciphertext encoding (Base64/Hex) must match the encrypting side exactly — any mismatch causes failure or garbage.

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