scrypt Calculator
Derive an scrypt key from a password and salt, with adjustable memory/CPU cost parameters — all in your browser.
About this tool
Uses scrypt-js, a well-known pure-JavaScript implementation of the scrypt key derivation function — not a hand-rolled version of the algorithm. scrypt's three cost parameters have a real relationship to memory use: roughly 128 × N × r bytes are needed during derivation, so large values can be slow or even freeze the tab — N must be a power of 2, and the inputs above are capped to keep things responsive in a browser. Defaults (N=16384, r=8, p=1) are the parameters from the original scrypt paper and a common baseline; check current guidance for your use case. Everything runs locally in your browser — no password is ever sent to a server.