Polyfills to support IE 11 and non ES6 browsers

Standard Polyfills for Front End

Getting your JavaScript applications working across all browsers is challenging. If you are writing your JavaScript using ES6 or ES5, then you are probably using some polyfills to be able to target old browsers (or Microsoft Edge). At the time of this post, Microsoft is rewriting Edge to be a chromium-based browser, which helps with cross-browser JavaScript discrepancies, but folks may not have upgraded Edge just yet.

One example of unsupported functionality in Edge includes the spread operator. The Babel library handles many cross-browser issues for you. If you need to support older browsers with current JavaScript frameworks, you should be using Babel. Babel will take care of polyfills like promises, spread operators, and more. Below is a list of polyfills that we use that Babel does not handle, which will get your applications working in browsers like Edge and IE11.

Fetch, most major browsers support fetch other then IE 11 Browser Support

Custom Events, most major browsers support Custom Events with only partial support in IE 11 Browser Support

URLSearchParams, most major browsers support URLSearchParams except for IE 11 Browser Support

Custom Elements, this has good support with Firefox and Chrome. Only the newest version of Edge natively supports Custom Elements Browser Support