Free AES Encrypt/Decrypt Tool

Yes, AES-256 is considered secure against all known attacks, including theoretical quantum computer attacks (which would only reduce it to AES-128 equivalent). It is approved for top-secret government data.

Without the password, encrypted data cannot be recovered. AES encryption is designed to be unbreakable without the key. Always store passwords securely and consider backup strategies.

Both are secure; AES-256 uses a longer key (256 bits vs 128) and more encryption rounds (14 vs 10). AES-256 provides more security margin but is slightly slower. Both are considered unbreakable.

GCM (Galois/Counter Mode) provides authenticated encryption - it encrypts data AND verifies it was not tampered with. If even one bit is changed, decryption fails. This prevents tampering attacks.

For most purposes, yes. Web Crypto API provides strong cryptographic primitives. However, browser security depends on your system. For highly sensitive data, use dedicated encryption software.

Only if you know the exact parameters used: algorithm, mode, key derivation, IV handling. Different tools may use different implementations. This tool is interoperable with its own format.