vanilla JS window width and height

window-height-width.js

const getViewportSize = () => {
  const e = document.documentElement;
  const g = document.getElementsByTagName('body')[0];
  const x = window.innerWidth || e.clientWidth || g.clientWidth;
  const y = window.innerHeight || e.clientHeight || g.clientHeight;
  return {x, y}
}