Encrypt and Decrypt Text

Type your text, enter a passphrase, and press Encrypt to get a single Base64 block back. To read it later, switch to Decrypt, paste that block, and enter the same passphrase. It all happens in your browser, and your passphrase never leaves the page.

It uses AES-256-GCM, an authenticated cipher, with your passphrase stretched into a key by PBKDF2 (SHA-256, 150,000 iterations) over a fresh random 16-byte salt, and a random 12-byte IV per message. The salt, IV, and ciphertext are packed into one Base64 string, so that single block plus your passphrase is all you need to decrypt.

There is no recovery. The key is derived from your passphrase alone, so if you forget it the text cannot be decrypted by you or by anyone else, including us. Because GCM verifies integrity, a wrong passphrase or any tampering with the encrypted block just returns an error rather than wrong text.

The cipher is genuinely strong, but the real security comes down to your passphrase. A short or common passphrase can be guessed no matter how good the algorithm is, so use something long and unique. The 150,000 PBKDF2 iterations slow down guessing, but they cannot rescue a weak passphrase.

No. The encryption and decryption run entirely in your browser using the Web Crypto API, and the passphrase never leaves the page. Relic, the product this tool comes from, is built on the same idea of encrypting on your device, though its app uses a different cipher rather than the AES-256-GCM here.