Online AES Encryption / Decryption
Online AES encryption tool built on Web Crypto API. Supports AES-GCM (recommended, authenticated) and AES-CBC. Key may be derived from a password (PBKDF2-SHA256) or supplied as a raw 16/24/32-byte hex key. Everything runs locally.
Usage
AES symmetric encryption. Two modes: self-contained (salt / IV packed into a single Base64 string) and interop (key, IV and ciphertext separately exposed for exchanging with other languages / systems).
Algorithms: AES-GCM (recommended, authenticated) / AES-CBC / AES-CTR (interop only). Password mode uses PBKDF2-SHA256 with a 16-byte random salt and 100,000 iterations.
Use cases
FAQ
AES-GCM or AES-CBC?
Prefer GCM — it includes an authentication tag that detects tampering. Use CBC only for legacy compatibility, and only with HMAC.
Is the password mode safe?
Uses PBKDF2-SHA256 with 16-byte random salt and 100,000 iterations. Weak passwords (like 123456) can still be brute-forced — use ≥ 12 chars.
Self-contained vs interop mode?
Self-contained packs salt + IV + ciphertext into one Base64 string. Interop exposes key / IV / ciphertext separately so other languages can consume it.
Why does decryption fail?
Wrong password, corrupted ciphertext, mismatched mode (GCM ciphertext won't decrypt as CBC), or wrong IV length in interop mode.