Encryption / Hash

AES Encrypt / Decrypt

AES-GCM symmetric encryption and decryption with passphrase-derived keys.

Plaintext
Password

What is AES Encryption?

AES (Advanced Encryption Standard) is a symmetric encryption algorithm widely used to protect sensitive data.

Features

  • Encrypt/Decrypt: Two-way conversion
  • Multiple Modes: CBC, ECB, CTR, GCM
  • Key Sizes: 128, 192, 256 bits

Use Cases

  • Data protection
  • Secure communication
  • File encryption

Frequently Asked Questions

The AES ciphertext differs every run — is something wrong?
No. Modern modes (CBC, CTR, GCM) generate a random IV per encryption, so the same plaintext never produces the same ciphertext — that randomness is a security feature. Decryption reads the IV carried with the ciphertext and recovers the exact plaintext.
128-bit or 256-bit key — how do I choose?
Neither has a known practical attack today: 128 is sufficient and slightly faster for most uses; 256 is headroom for "secret for decades" or compliance mandates. The real weak point is never key length — it is key management, which matters far more than the number.
AES-GCM versus AES-CBC?
GCM is authenticated encryption (AEAD): it produces a tag that detects any tampering, making it the default for new systems. CBC provides confidentiality only, and its history of padding-oracle vulnerabilities makes it a liability unless handled expertly. The Web Crypto API supports both; this tool offers each.