JSFiddle - React, Tailwind, and code Playground

HTML

<span id="clickMe_async" >CLICK (Asynchronous)</span>
<br/>
<span id="clickMe_sync" >CLICK (Synchronous)</span>

JavaScript

$('#clickMe_async').click(function(){
    $.ajax({
        url: document.location.href,
        type: 'post',
        async: true,
        success: function(data, textStatus){
            window.open('http://jquery.com/');
            //blocked
        }
    })
});

$('#clickMe_sync').click(function(){
    $.ajax({
        url: document.location.href,
        type: 'post',
        async: false,
        success: function(data, textStatus){
            window.open('http://jquery.com/');
            //pass
        }
    })
});