title: Why Firebase is so slow on mobile browsers?
body: <p>I've set up a simple app which pushes and fetches some data to and from Firebase.</p>
  
  <p>The relevant part of the code is:</p>
  
  <pre><code>var db = firebase.database();
  var notesRef = db.ref("notes");
  notesRef.on("child_added", function (item) {
      renderItem(item);
  }); 
  </code></pre>
  
  <p>While on desktop it loads relatively fast (2 seconds), on my iPhone (Safari on iOS 10), I have to wait about 15 seconds. My friends using Android have to wait even more.</p>
  
  <p>What is that happening at all? Why Firebase is so slow on the mobile devices?</p>
  
  <p>Is there a setting I have to enable or something like that?</p>