What is AES encryption?
AES (Advanced Encryption Standard) is the gold-standard symmetric cipher approved by NIST. AES-256-GCM combines 256-bit AES in Galois/Counter Mode, which provides both confidentiality (nobody can read the message) and authenticity (nobody can tamper with it undetected). This tool derives a 256-bit encryption key from your password using PBKDF2 with 100,000 SHA-256 iterations and a random 16-byte salt, then encrypts with a random 12-byte IV. The salt and IV are prepended to the ciphertext and Base64-encoded for portability. The result is compatible with any AES-256-GCM implementation that reads the same format.
How to use this tool
- 1 Enter a strong password — longer is better, avoid dictionary words.
- 2 Choose Encrypt, paste your plaintext, and click Encrypt.
- 3 Copy the Base64 ciphertext and store it securely.
- 4 To decrypt, switch to Decrypt mode, paste the ciphertext, enter the same password, and click Decrypt.
Frequently asked questions
Is the ciphertext portable to other tools?
The format is 16 bytes of salt + 12 bytes of IV + AES-256-GCM ciphertext, Base64-encoded. Any tool that knows this layout and uses PBKDF2-SHA256 with 100,000 iterations can decrypt it. The format is not a standard interchange format — it is specific to this tool.
What happens if I use the wrong password?
AES-GCM includes an authentication tag that verifies both the password and ciphertext integrity. A wrong password produces a decryption failure (OperationError) rather than garbled output — this is a security feature.
Why use PBKDF2 instead of the password directly?
Passwords are low-entropy text. PBKDF2 stretches the password into a 256-bit key using 100,000 hash iterations, making brute-force guessing 100,000× slower. The random salt ensures the same password produces a different key each time.
Is this tool safe for encrypting sensitive data?
The cryptography is sound — AES-256-GCM with PBKDF2 is standard practice. However, security also depends on your password strength and where you store the ciphertext. This tool does not manage passwords or keys for you.
Is my data sent to a server?
No. All encryption and decryption runs locally in your browser using the Web Crypto API. Your plaintext, password, and ciphertext never leave your device.