zstd‑codec provides JavaScript bindings to Facebook’s Zstandard compression library for both Node.js and browsers, compiled with Emscripten. It offers simple one‑shot compress/decompress functions as well as streaming and dictionary‑based APIs, letting developers handle small or large binary data directly in Uint8Array form. The package is aimed at JavaScript developers who need fast, loss‑less compression in server‑side or client‑side applications.