This page displays a list of IDE’s and sandbox examples I have built over the years and will continue to evolve over time. I use this list as a reference point for research in the IDE and sandbox category.
https://codesandbox.io - Clean easy to get started
https://jsfiddle.net/ - Clean easy to get started
https://codepen.io/ - Most popular among younger developers
https://phaser.io/sandbox - Game oriented
http://htmlsandbox.com - Simple approach
https://developer.paypal.com/reference/ - Great docs