Sucrase

Sucrase v3.35.1 is a super-fast JavaScript/TypeScript transpiler focused on modern JS runtimes. Unlike Babel or TypeScript, it only compiles non-standard language extensions (JSX, TypeScript, Flow) and ES modules to CommonJS, offering ~20x speed improvement. It ships TypeScript types, requires Node >=16 or 14.17+, and is actively maintained on GitHub. Primarily used for development builds where type checking is handled separately.