JSFiddle - React, Tailwind, and code Playground

JavaScript

var image = new Image();

image.onerror = function() {
   alert('Site not available');
};

image.onload = function() {
   alert('Site available');
};

// Works
//image.src = 'http://flickr.com/favicon.ico';

// Shouldn't work

image.src = 'http://idefinitelydontexistbutmaybeishould.com/favicon.ico';