Just some things to keep in mind when using babel.


In order for certain features to work they require certain polyfills. You can satisfy all Babel feature requirements by using the included polyfill.

You may alternatively selectively include what you need:

Feature Requirements
Abstract References Symbol
Array destructuring Symbol
Async functions, Generators regenerator runtime
Comprehensions Array.from
For Of Symbol, prototype[Symbol.iterator]
Spread Array.from


Built-in classes such as Date, Array, DOM etc cannot be properly subclassed due to limitations in ES5.


Since Babel assumes that your code will be run in an ES5 environment it uses ES5 functions. So if you're using an environment that has limited or no support for ES5 such as lower versions of IE then using the es5-shim along with the Babel polyfill will add support for these methods.

Internet Explorer

Classes (10 and below)

If you're inheriting from a class then static properties are inherited from it via __proto__, this is widely supported but you may run into problems with much older browsers.

NOTE: __proto__ is not supported on IE <= 10 so static properties will not be inherited. See the protoToAssign for a possible work around.

For classes that have supers, the super class won't resolve correctly. You can get around this by enabling loose mode for classes.

Getters/setters (8 and below)

In IE8 Object.defineProperty can only be used on DOM objects. This is unfortunate as it's required to set getters and setters. Due to this if you plan on supporting IE8 or below then the usage of getters and setters isn't recommended.

Reference: MDN.


By default, when using modules with Babel a non-enumerable __esModule property is exported. This is done through the use of Object.defineProperty which is unsupported in IE8 and below. A workaround for this is to enable loose mode - modules.