AES Encrypt
Encrypt and decrypt text with AES-GCM using a passphrase
About AES Encrypt
Encrypts text with AES-256-GCM using a key derived from your passphrase, and decrypts the resulting Base64 string back to plaintext. Key derivation and encryption run in your browser through the Web Crypto API, so neither the text nor the passphrase is uploaded. Useful for sending a short secret over chat or email, with the passphrase shared through another channel, or for keeping encrypted notes in a repository.
Category: Encoding.
Frequently asked questions
What is AES?
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Advanced Encryption Standard — a symmetric block cipher adopted by NIST in 2001. It is the most widely used encryption algorithm in the world, used in TLS, file encryption, disk encryption, and VPNs.
Which AES settings does this tool use?
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AES-256 in GCM mode. The key is derived from your passphrase with PBKDF2 (SHA-256, 100,000 iterations) and a random 16-byte salt, and every encryption uses a fresh 12-byte IV, so the same text encrypts differently each time.
What does the encrypted output contain?
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A single Base64 string holding the 16-byte salt, the 12-byte IV and the ciphertext followed by its 16-byte authentication tag. To decrypt it elsewhere, split those parts and repeat the same PBKDF2 and AES-GCM steps; OpenSSL enc and CryptoJS use different formats and cannot read it.
What happens if I enter the wrong passphrase?
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Decryption fails with an error instead of returning garbled text, because GCM checks the authentication tag; the same check catches modified or truncated ciphertext. A lost passphrase cannot be recovered, and a short or common one can be brute-forced, so use a long, random passphrase.