AES Encrypt / Decrypt
Encrypt and decrypt with AES-CBC locally. Your key and text never leave this device.
01
Input and key
Enter plaintext to encrypt, or paste ciphertext to decrypt
All operations are performed in your current browser.
02
Result
Copy the output or send it back to the input for another operation
Tool guide
Defaults to AES-CBC + PKCS7. Output format is ivBase64:cipherBase64. This is a local demo tool with no key custody — not for production key management.
- Keys and content are processed only in your browser
- To decrypt, paste full iv:ciphertext, or fill IV separately
- Not a password-storage solution
FAQ
What is the ciphertext format?
Encryption output is two Base64 parts: ivBase64:cipherBase64.
Is my data uploaded?
No. Encryption and decryption stay local.
Does it support AES-256-CBC?
Yes. Key length follows the input string byte count: 16, 24, and 32 bytes map to AES-128, AES-192, and AES-256. Encryption uses CBC mode with PKCS7 padding.
Why does decryption fail?
The usual causes are a mismatched key, a wrong IV, or incomplete ciphertext. When no IV is given during encryption, a random one is generated and prepended as ivBase64 — decryption needs that same IV and key.