SystemJS Document

Unofficial SystemJS documentation.

Dynamic ES module loader.

Module Loader

SystemJS is a hookable, standards-based module loader that enables code written for native ES modules in browsers to be transpiled and work in older browsers. It supports features like dynamic import, circular references, and import maps.

Transpiler

SystemJS provides a transpilation mechanism that converts code written for modern native ES modules into the System.register module format. This allows developers to ensure compatibility with older browsers that do not support native modules.

Advanced Features

SystemJS offers advanced features such as top-level await, import.meta.url, module types, integrity, and Content Security Policy. It also maintains compatibility with older browsers, including IE11, while providing almost-native module speeds.