This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.


This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

This method is called periodically as an event handler for progress events on XDomainRequests, so that code can monitor progress while loading content.

Note: While handling this event, you can look at XDomainRequest.responseText to get the response so far.

Once loading is complete, the XDomainRequest.onload event handler gets called.


xdr.onprogress = funcRef;


A function to call when progress events occur.


var xdr = new XDomainRequest();
xdr.open("POST", "http://example.com/api/method");

xdr.onprogress = function(){
  //Handle Partial Response with xdr.responseText

xdr.onload = function(){
  //Handle Response with xdr.responseText



Not part of any specification.

Browser compatibility

BCD tables only load in the browser