Not sure where I can get a fiddle that makes a 4xx error that includes a response, but here's a starting fiddle http://jsfiddle.net/IDisposable/2LxPW/1/

Added a pull request implementing option 1 https://github.com/jquery/jquery/pull/1552

Kind of shows that it would be nicer to do option 2, but then the response object isn't known to to the success case since we don't pass the jqXHR object to that resolve.

The jqXHR object already has response fields (response, responseXML and responseJSON) that are available in both resolved and rejected states. So I'm not sure what you're asking for here.

I don't see that in http://jsfiddle.net/IDisposable/2LxPW/4/ (hitting a twitter endpoint that has a text response to a 401)

The console.log(jqXHR) gives

Object {readyState: 0, getResponseHeader: function, getAllResponseHeaders: function, setRequestHeader: function, overrideMimeType: function…}
abort: function ( statusText ) {
always: function () {
complete: function () {
done: function () {
error: function () {
fail: function () {
getAllResponseHeaders: function () {
getResponseHeader: function ( key ) {
overrideMimeType: function ( type ) {
pipe: function ( /* fnDone, fnFail, fnProgress */ ) {
progress: function () {
promise: function ( obj ) {
readyState: 0
setRequestHeader: function ( name, value ) {
state: function () {
status: 0
statusCode: function ( map ) {
statusText: "error"
success: function () {
then: function ( /* fnDone, fnFail, fnProgress */ ) {
__proto__: Object

What I'm trying to accomplish is when there is an error state, having access to the actual response (hopefully fully parsed for JSON or XML) since we have that already done in the done method of $.ajax.

That seems very fishy to me. responseXXX fields are set in ajaxConvert ( https://github.com/jquery/jquery/blob/master/src/ajax.js#L216 ) which is called for both success and errors ( https://github.com/jquery/jquery/blob/master/src/ajax.js#L691 ). It uses the global option set in ajaxSettings ( https://github.com/jquery/jquery/blob/master/src/ajax.js#L332 ) which references text, XML and JSON dataTypes.

Unless you're using an older version of jQuery or response headers are not set up properly, those fields will be set.

Also, we're supposedly dealing with a 401 but look at the status on the jqXHR instance:

status: 0

Seems to me there's something wrong with the test case.

Ah, but the s (created at https://github.com/jquery/jquery/blob/master/src/ajax.js#L691 ) is NOT the jqXHR (created at https://github.com/jquery/jquery/blob/master/src/ajax.js#L428 ) of line 216 is NOT the jqXHR of line 741 et al. They are different objects entirely. The result of ajaxConvert from https://github.com/jquery/jquery/blob/master/src/ajax.js#L691 is assigned to a local that I just want passed to the deferred resolves of various ilk so I can reach up and get the raw text or JSON or XML as parsed.

You can see from the jsFiddle that it was running against 2.1, but here's a new and improved one against 2.x http://jsfiddle.net/IDisposable/2LxPW/5/ which still shows that the jqXHR does NOT have the responses handy.

You have no response because the actual request was not issued. It's a CORS issue you have here, hence why the status is 0. That's pretty obvious when you open your favorite development tool:

XMLHttpRequest cannot load https://api.twitter.com/oauth/access_token. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://fiddle.jshell.net' is therefore not allowed access. 

Have you tried with a same-domain setup? Because we do have unit tests regarding those responseXXX fields: https://github.com/jquery/jquery/blob/master/test/unit/ajax.js#L1391

Also, jqXHR actually is the same object throughout the whole ajax request. Objects are passed by reference in JavaScript.