PBKDF2 Key Derivation
Derive a cryptographic key from a password using PBKDF2 (Password-Based Key Derivation Function 2), the standard KDF for turning a human password into a fixed-length key suitable for encryption or storage. It applies a keyed HMAC many thousands of times over your password and a salt, making brute-force guessing expensive. Everything runs locally via your browser's Web Crypto API — the password never leaves your device.
Derive a key
Verify a password against a known key
PBKDF2 (RFC 2898 / PKCS#5) stretches a password into a key by computing HMAC-Hash(password, salt ‖ INT(i)) for each block, repeated iterations times — so an attacker must spend iterations HMAC operations per guess. The salt should be a unique random value per password (prevents rainbow-table and precomputation attacks); it is not secret and is stored alongside the derived key. The iteration count is the main cost knob — OWASP recommends at least 600,000 for PBKDF2-HMAC-SHA256 (or 1,300,000 for SHA-1) as of 2023. The key length is in bits and must be a multiple of 8. This tool uses your browser's native SubtleCrypto.deriveBits, so the password and salt are processed entirely on-device and never transmitted. For password storage prefer a memory-hard KDF (Argon2/bcrypt/scrypt) over raw PBKDF2; PBKDF2 shines for deriving encryption keys. Pairs with the bcrypt, HMAC, and hash generators. Everything runs locally — nothing leaves your browser.