About the AES Encrypt and Decrypt Tool
Use this AES tool to encrypt plaintext into ciphertext or decrypt AES ciphertext back into readable text when you have the correct key and matching settings. This page is designed for text-based AES testing, learning, and troubleshooting.
AES, short for Advanced Encryption Standard, is a symmetric block cipher. Encryption and decryption use the same secret key. This tool supports common AES key sizes: 128-bit, 192-bit, and 256-bit. Choose the mode, padding, IV, key, and output encoding that match your test case.
• How to Use It
Enter plaintext to encrypt or ciphertext to decrypt.
Select an AES mode such as ECB, CBC, CTR, OFB, or CFB.
Choose padding when your selected mode and data require it.
Provide the key and IV required by your settings.
Select Base64 or Hex for the ciphertext display format.
Use encrypt or decrypt to generate the result.
• Important Notes
For decryption, the key, mode, padding, IV, and input encoding must match the original encryption settings. A small mismatch can produce unreadable output or a failed result.
Do not reuse the same IV with the same key in modes that require a unique IV. ECB mode is included for compatibility and testing, but it is usually not recommended for real security use because repeated plaintext patterns may remain visible.
Base64 and Hex are output encodings, not encryption methods. They only control how ciphertext is displayed or copied.
• Common Uses
Test AES encryption and decryption with sample text.
Compare AES-128, AES-192, and AES-256 settings.
Troubleshoot AES results from applications, APIs, or backend services.
Check whether mode, padding, IV, key length, and output encoding are compatible across systems.