How to use AES-GCM
- 1. Enter a passphrase. Skip this on a shared computer.
- 2. Paste plaintext. Or drop a text file.
- 3. Encrypt. You get Base64 of salt+IV+ciphertext.
- 4. Decrypt. Same passphrase, same payload.
About this tool
AES-GCM is the authenticated cipher browsers actually ship. A passphrase is stretched with PBKDF2 so you are not using a 4-character password as a raw AES key. This is a notebook, not a vault product.
What's in the blob
16-byte salt, 12-byte IV, then ciphertext+tag. Lose any of it and decryption fails.
Not a password manager
There is no recovery. 100k PBKDF2 iterations is a floor, not Argon2.
Code examples
Web Crypto
crypto.subtle.encrypt({ name: "AES-GCM", iv }, key, data)