Babel.js is a JavaScript compiler. Babel is a toolchain that is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript in current and older browsers or environments.

Here are the main things Babel can do for you:

• Transform syntax
• Polyfill features that are missing in your target environment (through @babel/polyfill)
• Source code transformations (codemods)
• And more! (check out these videos for inspiration)

Learn ES2015

Polyfill

It’s a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.