JavaScript, widely used for everything from simple websites to complex applications, has many lesser-known features that can enhance your code. These include the nullish coalescing operator for handling null or undefined values, optional chaining for safe access of nested properties, the double bang operator for boolean conversion, dynamic key access in objects using optional chaining, and methods like Object.fromEntries() for transforming lists into objects. Other noteworthy features include dynamic module imports, Proxy objects for meta-programming, the Reflect API for default operations, tagged template literals for custom string processing, and the Intl object for internationalization.