Web Browser support

All major browsers support AJAX. The XMLHttpRequest object is supported by all the modern browsers (Firefox, Chrome, Internet Explorer 7 and up)

Now a days, all modern browsers (Internet Explorer 7 and up, Firefox, Chrome, etc.) have a built-in XMLHttpRequest object. For Internet Explorer 5 and 6, you can create an ActiveXObject to perform AJAX operations, for instance you can do the following:

Syntax for creating an XMLHttpRequest object:

var xmlHTTPRequest;
if (window.XMLHttpRequest)
  {// Validation for Internet Explorer 7 and upo, Firefox, Chrome, etc
 xmlHTTPRequest = new XMLHttpRequest();
  }
else
  {// Web browser is Internet Explorer 5 or 6
 xmlHTTPRequest = new ActiveXObject("Microsoft.XMLHTTP");
  }