Request header field Access-Control-Allow-Headers is not allowed by Access-Control-Allow-Headers

Javascript Problem Overview

I'm trying to send files to my server with a post request, but when it sends it causes the error:

>Request header field Content-Type is not allowed by Access-Control-Allow-Headers.

So I googled the error and added the headers:

$http.post($rootScope.URL, {params: arguments}, {headers: {
    "Access-Control-Allow-Origin" : "*",
    "Access-Control-Allow-Methods" : "GET,POST,PUT,DELETE,OPTIONS",
    "Access-Control-Allow-Headers": "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With"
}

Then I get the error:

>Request header field Access-Control-Allow-Origin is not allowed by Access-Control-Allow-Headers

So I googled that and the only similar question I could find was provided a half answer then closed as off topic. What headers am I supposed to add/remove?

Javascript Solutions

Solution 1 - Javascript

I had the same problem. In the jQuery documentation I found:

> For cross-domain requests, setting the content type to anything other than application/x-www-form-urlencoded, multipart/form-data, or text/plain will trigger the browser to send a preflight OPTIONS request to the server.

So though the server allows cross origin request but does not allow Access-Control-Allow-Headers , it will throw errors. By default angular content type is application/json, which is trying to send a OPTION request. Try to overwrite angular default header or allow Access-Control-Allow-Headers in server end. Here is an angular sample:

$http.post(url, data, {
    headers : {
        'Content-Type' : 'application/x-www-form-urlencoded; charset=UTF-8'
    }
});

Solution 2 - Javascript

The server (that the POST request is sent to) needs to include the Access-Control-Allow-Headers header (etc) in its response. Putting them in your request from the client has no effect. You should remove the 'Access-Control-Allow-...' headers from your POST request.

This is because it is up to the server to specify that it accepts cross-origin requests (and that it permits the Content-Type request header, and so on) – the client cannot decide for itself that a given server should allow CORS.

The requestor (web browser) may 'preflight' test what the server's Same Origin Policy is by sending an 'OPTIONS' request (ie not the 'POST' or 'GET' request you intend). If the response to the 'OPTIONS' request contains 'Access-Control-Allow-...' headers that permit the headers, origin, or methods your request is using, then the requester/browser will send your 'POST' or 'GET' request.

(obscure note:) The Access-Control-Allow-... have the value '' rather than listing the specific origin, headers, or methods allowed. However, and old Android WebView client I was using didn't honor the '' wildcard and needed the specific headers listed in the Access-Control-Allow-Headers header in the response to the OPTIONS request.

Solution 3 - Javascript

If that helps anyone, (even if this is kind of poor as we must only allow this for dev purpose) here is a Java solution as I encountered the same issue. [Edit] Do not use the wild card * as it is a bad solution, use localhost if you really need to have something working locally.

public class SimpleCORSFilter implements Filter {

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
    HttpServletResponse response = (HttpServletResponse) res;
    response.setHeader("Access-Control-Allow-Origin", "my-authorized-proxy-or-domain");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");
    chain.doFilter(req, res);
}

public void init(FilterConfig filterConfig) {}

public void destroy() {}

}

Solution 4 - Javascript

The server (that the POST request is sent to) needs to include the Content-Type header in its response.

Here's a list of typical headers to include, including one custom "X_ACCESS_TOKEN" header:

"X-ACCESS_TOKEN", "Access-Control-Allow-Origin", "Authorization", "Origin", "x-requested-with", "Content-Type", "Content-Range", "Content-Disposition", "Content-Description"

That's what your http server guy needs to configure for the web server that you're sending your requests to.

You may also want to ask your server guy to expose the "Content-Length" header.

He'll recognize this as a Cross-Origin Resource Sharing (CORS) request and should understand the implications of making those server configurations.

For details see:

Solution 5 - Javascript

You can activate the proper header in PHP with this:

header('Access-Control-Allow-Origin: *');
header("Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT, DELETE");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, X-Requested-With");

Solution 6 - Javascript

The following works for me with nodejs:

xServer.use(function(req, res, next) {
  res.setHeader("Access-Control-Allow-Origin", 'http://localhost:8080');
  res.setHeader('Access-Control-Allow-Methods', 'POST,GET,OPTIONS,PUT,DELETE');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type,Accept');

  next();
});

Solution 7 - Javascript

If you are using localhost and PHP set to this to solve the issue:

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Headers: Content-Type');

From your front-end use:

{headers: {"Content-Type": "application/json"}}

and boom no more issues from localhost!

Solution 8 - Javascript

In Asp Net Core, to quickly get it working for development; in Startup.cs, Configure method add

app.UseCors(options => options.AllowAnyOrigin().AllowAnyMethod().AllowAnyHeader());

Solution 9 - Javascript

The headers you are trying to set are response headers. They have to be provided, in the response, by the server you are making the request to.

They have no place being set on the client. It would be pointless having a means to grant permissions if they could be granted by the site that wanted permission instead of the site that owned the data.

Solution 10 - Javascript

If anyone experiences this problem with an express server, add the following middleware

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
  next();
});

Solution 11 - Javascript

In my case, I'm receiving several parameters as @HeaderParam into a web service method.

These parameters MUST be declared in your CORS filter that way:

@Provider
public class CORSFilter implements ContainerResponseFilter {

    @Override
    public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) throws IOException {

        MultivaluedMap<String, Object> headers = responseContext.getHeaders();

	    headers.add("Access-Control-Allow-Origin", "*");
	    ...
	    headers.add("Access-Control-Allow-Headers", 
	    /*
	     * name of the @HeaderParam("name") must be declared here (raw String):
	     */
	    "name", ...);
	    headers.add("Access-Control-Allow-Credentials", "true");
	    headers.add("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD");	
    }
}

Solution 12 - Javascript

if you testing some javascript requests for ionic2 or angularjs 2 , in your chrome on pc or mac , then be sure that you install CORS plugin for chrome browser to allow cross origin .

mayba get requests will work without needing that , but post and puts and delete will need you to install cors plugin for testing to go without problems , that definitley not cool , but i do not know how people do it without CORS plugin .

and also be sure the json response is not returning 400 by some json status

Solution 13 - Javascript

this is backend problem. if use sails api on backend change cors.js and add your filed here

module.exports.cors = {
  allRoutes: true,
  origin: '*',
  credentials: true,
  methods: 'GET, POST, PUT, DELETE, OPTIONS, HEAD',
  headers: 'Origin, X-Requested-With, Content-Type, Accept, Engaged-Auth-Token'
};

Solution 14 - Javascript

Request header field Access-Control-Allow-Origin is not allowed by Access-Control-Allow-Headers error means that Access-Control-Allow-Origin field of HTTP header is not handled or allowed by response. Remove Access-Control-Allow-Origin field from the request header.

Solution 15 - Javascript

For me, Added the following to my server's web.config file:

<system.webServer>
    <httpProtocol>
    	<customHeaders>
			<add name="Access-Control-Allow-Origin" value="https://other.domain.com" />
			<add name="Access-Control-Allow-Methods" value="GET,POST,OPTIONS,PUT,DELETE" />
			<add name="Access-Control-Allow-Headers" value="Content-Type,X-Requested-With" />
        </customHeaders>
    </httpProtocol>
<system.webServer>

Solution 16 - Javascript

For me I had wildcard "*" Access-Control-Allow-Headers in web.config:

<add name="Access-Control-Allow-Headers" value="*" />

This solution works for most navigators but not for Safari or IE

It turned out the solution was to add manually all the custom header to the web.config:

<system.webServer>
    <httpProtocol>
        <customHeaders>
            <add name="Access-Control-Allow-Origin" value="https://somedomain.com" />
            <add name="Access-Control-Allow-Methods" value="GET,POST,OPTIONS,PUT,DELETE" />
            <add name="Access-Control-Allow-Headers" value="custom-header1, custome-header2, custome-header3" />
        </customHeaders>
    </httpProtocol>
<system.webServer>

Content Type	Original Author	Original Content on Stackoverflow
Question	user3194367	View Question on Stackoverflow
Solution 1 - Javascript	Fisherman	View Answer on Stackoverflow
Solution 2 - Javascript	Shai	View Answer on Stackoverflow
Solution 3 - Javascript	lekant	View Answer on Stackoverflow
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