Detect when a browser page window loses focus with Alt-Tab using pure JS or jQuery

Question

Is it possible to detect current page is in alt-tab? This code works only if a new tab in browser is opened:

(function() {
  var hidden = \"hidden\";

  // S         


        

Answer 1

There is a Page Visibility API available: https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API

document.addEventListener("visibilitychange", handleVisibilityChange, false)