How This AES Encrypt / Decrypt Tool Works
Type or paste text, pick a key size, and this aes encrypt decrypt online tool, a genuine encrypt text with password online workflow, derives a key from your password and encrypts the text with AES-GCM, the output is a single aes-gcm online encrypt result: one Base64 blob combining a random salt, a random IV, and the ciphertext, ready to copy or download. Switch to Decrypt mode, paste that Base64 blob back in with the same password, and this decrypt aes online free workflow reverses it exactly, nothing about the process touches a server at any point.
Why AES-GCM Instead of AES-CBC?
AES-GCM is authenticated encryption, meaning it detects tampering: decrypting with the wrong password or a corrupted ciphertext fails outright instead of silently returning garbage plaintext, the way older modes like AES-CBC can. That authentication tag is baked into the ciphertext automatically, there's no separate MAC to manage, which is why this aes-gcm password based encryption tool, like most modern aes text encryption tool implementations, defaults to GCM over CBC or ECB, GCM is simply the safer default for encrypting text with a password today.
How the Password Becomes a Key (PBKDF2)
A password on its own isn't a valid AES key, it needs to be turned into one first, and doing that naively, say, hashing it once, makes brute-forcing weak passwords far too fast. This pbkdf2 aes encryption tool instead runs your password through PBKDF2 with a random 16-byte salt and 100,000 SHA-256 iterations, deliberately slowing down key derivation so guessing passwords against a captured ciphertext takes meaningfully longer. The salt is random per encryption and travels with the ciphertext, not secret, just unique, so identical plaintext encrypted twice with the same password still produces completely different output.
Common Uses
Sharing a sensitive note or credential over a channel you don't fully trust, encrypting a config value or API key before storing it somewhere semi-public, and quickly testing how your own AES-GCM implementation should behave against a known-good tool are the most common reasons developers reach for this aes 128 192 256 encrypt tool. It's also useful as a client side aes encryption reference when implementing the same PBKDF2 plus AES-GCM pattern in a real application, the parameters here, iteration count, salt size, IV size, are exactly what a production implementation should use.