Encrypt / decrypt a file (local AES)

Encrypt a file with AES-256-GCM using a password, or decrypt a file encrypted by this tool. All processing — key derivation (PBKDF2), encryption and decryption — happens locally via your browser's WebCrypto API: neither the file nor the password ever leaves your device.

Choose a strong password: without it, the encrypted file cannot be recovered.

How it works

When encrypting, a random salt and initialization vector (IV) are generated, an AES-256 key is derived from your password via PBKDF2 (250,000 iterations, SHA-256), then the file is encrypted with AES-GCM (which guarantees both confidentiality and integrity). The salt, IV, and ciphertext are assembled into a single downloadable file (.enc extension): nothing else is needed to decrypt it, except the password.

What happens if I forget the password?

The encrypted file becomes permanently unrecoverable. There is no backdoor or recovery mechanism: that's precisely what guarantees no one else can decrypt the file without knowing the password.

Is this format compatible with other encryption tools?

No: the file format produced here (tool-specific header, followed by the salt, IV, then AES-GCM ciphertext) is specific to this page. A file encrypted here can only be decrypted with this same page (or an exact reimplementation of the same format), not with OpenSSL or any other generic encryption tool.

Privacy: the file and password remain 100% local — encryption and decryption happen entirely in your browser via the native WebCrypto API, with no network upload.