How to make ES6 codes compatible to any devices?

Question

I'm planning to migrate to ES6 on real projects but don't know how to deal with devices which does not support ES6 syntax. How do you get rid of it aside from not using ES6 (Lol)?

Answer 1

refer to here:
https://www.sololearn.com/Discuss/1220172/?ref=app

Original
https://code.sololearn.com/Wb7NApdNl761/?ref=app

Babel transpiled
https://code.sololearn.com/WH9RiWIgduqP/?ref=app

all i changed was adding the following
to HTML:
Babel script
<script src="https://unpkg.com/babel-standalone@latest/babel.min.js"></script>

to JS (on top):
//</script><script type="text/babel">

Answer 2

As what Burey refered, you could use Babel transpiler for older browsers that not support ES6.