How can I add a custom HTTP header to ajax request with js or jQuery?

javascript jquery ajax http-headers httprequest

472,133

Solution 1

There are several solutions depending on what you need...

If you want to add a custom header (or set of headers) to an individual request then just add the headers property:

// Request with custom header
$.ajax({
    url: 'foo/bar',
    headers: { 'x-my-custom-header': 'some value' }
});

If you want to add a default header (or set of headers) to every request then use $.ajaxSetup():

$.ajaxSetup({
    headers: { 'x-my-custom-header': 'some value' }
});

// Sends your custom header
$.ajax({ url: 'foo/bar' });

// Overwrites the default header with a new header
$.ajax({ url: 'foo/bar', headers: { 'x-some-other-header': 'some value' } });

If you want to add a header (or set of headers) to every request then use the beforeSend hook with $.ajaxSetup():

$.ajaxSetup({
    beforeSend: function(xhr) {
        xhr.setRequestHeader('x-my-custom-header', 'some value');
    }
});

// Sends your custom header
$.ajax({ url: 'foo/bar' });

// Sends both custom headers
$.ajax({ url: 'foo/bar', headers: { 'x-some-other-header': 'some value' } });

Edit (more info): One thing to be aware of is that with ajaxSetup you can only define one set of default headers and you can only define one beforeSend. If you call ajaxSetup multiple times, only the last set of headers will be sent and only the last before-send callback will execute.

Solution 2

Or, if you want to send the custom header for every future request, then you could use the following:

$.ajaxSetup({
    headers: { "CustomHeader": "myValue" }
});

This way every future ajax request will contain the custom header, unless explicitly overridden by the options of the request. You can find more info on ajaxSetup here

Solution 3

You can also do this without using jQuery. Override XMLHttpRequest's send method and add the header there:

XMLHttpRequest.prototype.realSend = XMLHttpRequest.prototype.send;
var newSend = function(vData) {
    this.setRequestHeader('x-my-custom-header', 'some value');
    this.realSend(vData);
};
XMLHttpRequest.prototype.send = newSend;

Solution 4

Assuming JQuery ajax, you can add custom headers like -

$.ajax({
  url: url,
  beforeSend: function(xhr) {
    xhr.setRequestHeader("custom_header", "value");
  },
  success: function(data) {
  }
});

Solution 5

Here's an example using XHR2:

function xhrToSend(){
    // Attempt to creat the XHR2 object
    var xhr;
    try{
        xhr = new XMLHttpRequest();
    }catch (e){
        try{
            xhr = new XDomainRequest();
        } catch (e){
            try{
                xhr = new ActiveXObject('Msxml2.XMLHTTP');
            }catch (e){
                try{
                    xhr = new ActiveXObject('Microsoft.XMLHTTP');
                }catch (e){
                    statusField('\nYour browser is not' + 
                        ' compatible with XHR2');                           
                }
            }
        }
    }
    xhr.open('POST', 'startStopResume.aspx', true);
    xhr.setRequestHeader("chunk", numberOfBLObsSent + 1);
    xhr.onreadystatechange = function (e) {
        if (xhr.readyState == 4 && xhr.status == 200) {
            receivedChunks++;
        }
    };
    xhr.send(chunk);
    numberOfBLObsSent++;
};

Hope that helps.

If you create your object, you can use the setRequestHeader function to assign a name, and a value before you send the request.

View more solutions

472,133

Author by

Txugo

Software Developer @London

Updated on July 16, 2022

Comments

Txugo almost 2 years

Does anyone know how to add or create a custom HTTP header using JavaScript or jQuery?
Trip over 11 years

Where i really want to accomplish this, this doesn't seem to actually work.
Szilard Muzsi over 11 years

Well you should make sure that the ajaxSetup is called before the actual ajax call. I don't know of any other reason why this wouldn't work :)
Kostas almost 11 years

What happens if I define a new beforeSend when doing a $.ajax?
Prestaul almost 11 years

You can only define one beforeSend callback. If you call $.ajaxSetup({ beforeSend: func... }) twice then the second callback will be the only one that fires.
Prestaul almost 11 years

Updated my answer to add more details about ajaxSetup.
Dan Dascalescu over 9 years

While this may have been correct in 2011, it's generally a good idea to not reinvent the wheel, and instead use an AJAX library like Zepto or jQuery.
roryhewitt over 9 years

Unless you are trying to add a header to an existing XHR2 call and don't want to start rewriting it all to use jQuery just for that... At which point, @gryzzly has the only viable answer.
user1940268 over 9 years

Hi all, headers: { 'x-my-custom-header': 'some value' } doesn't work in IE 8. it works fine in firefox and chrome. I have to send custom headers using IE 8. Have you some idea to make it work? Thx
Prestaul over 9 years

@user1940268 are you trying to do a cross domain (CORS) request or some other type of custom header? I've certainly used all of these techniques in IE8 and am certain they work. The one exception is xDomain requests where you need another technique in IE8.
user1940268 over 9 years

@Prestaul thx for your reply. My ajax request is in the same domain. $(document).ready(function() { $.ajax({ url: url, type: "POST", headers: { 'x-my-custom-header': 'some value' } }); });
Prestaul over 9 years

@user1940268, I think there must be something else going on outside of the posted code (possibly server-side when trying to read the headers). your ajax call looks right and I don't think I'm going to be able to help you here.
svassr about 9 years

Looks like it doesn't work with CORS Request (every browser). Is there a work around ?
svassr about 9 years

found my solution here stackoverflow.com/questions/8685678/…
Prestaul about 9 years

@svassr CORS has different requirements and, as you found out, beyond a few (very basic) headers, any additional will have to be whitelisted via the Access-Control-Request-Headers header.
Kevin Lee over 7 years

For my case, I wanted the http header accept value to be strictly just text/plain. ajax's accepts behavior really tripped me up. It kept adding an extra */* to the end, after my text/plain. Sigh. Specifying the headers works better.
Si8 over 7 years

I get this error: Response to preflight request doesn't pass access control check
Prestaul about 7 years

@Si8, that looks like a cross domain issue to me. You can't make a request from one domain to another. Try looking into CORS and see if that helps.
Cobertos about 7 years

@AliGajani The problem is that certain applications or libraries (like THREE.js) don't use $.ajax* functions b/c they don't depend on jQuery and instead use XHR so this is the only valid option in those cases.
Oztaco over 6 years

@AliGajani Additionally, it's not just the network load time but the parsing time of the library. Plus, if you are not careful with what dependencies you add, you can quickly get a project with too many dependencies
mrid over 3 years

These don't really work. I tried them and they change my request to options from post or get
llange almost 3 years

Mind that in JS you will set the header with hyphens and it will be accessible from PHP using underscores prepended by HTTP_ Eg. $.ajaxSetup({headers:{'X-MY-CUSTOM-HEADER':'somevalue'}); can the be access from PHP via $_SERVER['HTTP_X_MY_CUSTOM_HEADER']