AES-256 Encryption & Decryption
Encrypt and decrypt text using AES-256-GCM — the strongest AES mode. Runs entirely in your browser using the Web Crypto API.
What Is AES Encryption?
AES (Advanced Encryption Standard) is a symmetric encryption algorithm adopted by the US government in 2001 and now used worldwide to protect sensitive data. It comes in three key sizes: 128-bit, 192-bit, and 256-bit. This tool uses AES-256, which provides the largest security margin and is recommended for protecting sensitive information.
This tool specifically uses AES-256-GCM (Galois/Counter Mode), the most secure and recommended AES mode. GCM provides both encryption (confidentiality) and authentication (data integrity) — meaning you can detect if the encrypted data has been tampered with. The password is converted to a 256-bit key using PBKDF2 with 100,000 iterations, which makes brute-force attacks computationally expensive.
How It Works
When you encrypt text, the tool generates a random 16-byte salt and 12-byte IV (initialization vector), derives a 256-bit key from your password using PBKDF2-SHA256, encrypts the text using AES-256-GCM, and outputs everything combined as a Base64 string. To decrypt, it extracts the salt and IV from the Base64 string and reconstructs the key using the same password. Without the correct password, decryption is computationally infeasible.