Encryption Decryption Tool
Encrypt text into an AES-GCM JSON envelope or decrypt an envelope created by this page using the same passphrase.
Last updated: May 28, 2026
Do not paste production secrets, private keys, customer data, or regulated data into browser tools unless your organization allows that workflow.
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Buy me a coffeeWhat is Encryption Decryption?
This encryption/decryption tool uses the browser Web Crypto API to encrypt text with AES-GCM. A passphrase is converted into a 256-bit AES key using PBKDF2-SHA-256 with a random salt. The output is a JSON envelope containing the algorithm, KDF settings, salt, IV, and ciphertext needed to decrypt later with the same passphrase.
How to Use Encryption Decryption
Choose Encrypt or Decrypt.
For encryption, paste plain text and enter a passphrase.
Click Encrypt Text and copy the JSON envelope.
For decryption, paste that JSON envelope and enter the same passphrase.
Click Decrypt Text to recover the original text.
Common Use Cases
- Encrypting local demo notes before sharing through a non-secret channel.
- Testing AES-GCM and PBKDF2 flows in a browser.
- Creating reproducible examples for documentation or training.
- Verifying that an encrypted payload can round-trip with a passphrase.
- Learning what metadata is required to decrypt AES-GCM ciphertext.
Example Input and Output
A plaintext note is encrypted into a JSON envelope. The same passphrase is required to decrypt it.
Database password rotation is scheduled for Friday at 22:00 UTC.{
"v": 1,
"alg": "AES-GCM",
"kdf": "PBKDF2-SHA-256",
"iterations": 120000,
"salt": "...",
"iv": "...",
"ciphertext": "..."
}Passphrase quality
A strong passphrase matters. AES-GCM is strong, but a short or reused passphrase can still be guessed.
Browser-side crypto
The browser Web Crypto API performs key derivation, encryption, and decryption locally.