What this tool is good for
Symmetric encryption uses the same secret key for encryption and decryption. It is usually faster than asymmetric encryption and is well suited to larger amounts of data, but the shared key must be protected carefully.
This page supports common symmetric algorithms including AES, TripleDES, Rabbit, RC4, and DES for quick browser-side testing and interoperability work.
AES notes
AES is one of the most widely used symmetric ciphers. The tool supports AES-128, AES-192, and AES-256. When you use the simple passphrase mode rather than custom key/IV input, the default behavior corresponds to AES-256-CBC.
Custom AES mode supports CBC, CFB, CTR, OFB, and ECB, together with common padding modes such as Pkcs7, Iso97971, AnsiX923, Iso10126, ZeroPadding, and NoPadding.
Other supported ciphers
- DES and TripleDES: legacy algorithms mainly kept for compatibility work.
- Rabbit: a high-performance stream cipher from the eSTREAM portfolio.
- RC4: a classic stream cipher seen in older systems and protocols.
Common mistakes
- The key, IV, mode, and padding must match exactly between encryption and decryption.
- ECB does not use an IV, while modes such as CBC and CFB do.
- DES and RC4 are legacy choices and should usually be used only for compatibility testing.
Related tools
- ChaCha20 Encrypt & Decrypt：Encrypt and decrypt data with ChaCha20
- RSA Encryption & Decryption：Encrypt and decrypt short text with RSA in your browser