The Access-Control-Allow-Origin response header indicates whether the response can be shared with requesting code from the given origin.

Header type Response header
Forbidden header name no


Access-Control-Allow-Origin: *
Access-Control-Allow-Origin: <origin>
Access-Control-Allow-Origin: null


For requests without credentials, the literal value "*" can be specified, as a wildcard; the value tells browsers to allow requesting code from any origin to access the resource. Attempting to use the wildcard with credentials will result in an error.
Specifies an origin. Only a single origin can be specified.


A response that tells the browser to allow code from any origin to access a resource will include the following:

Access-Control-Allow-Origin: *

A response that tells the browser to allow requesting code from the origin to access a resource will include the following:


Limiting the possible Access-Control-Allow-Origin values to a set of allowed origins requires code on the server side to check the value of the Origin request header, compare that to a list of allowed origins, and then if the Origin value is in the list, to set the Access-Control-Allow-Origin value to the same value as the Origin value.

CORS and caching

If the server sends a response with an Access-Control-Allow-Origin value that is an explicit origin (rather than the "*" wildcard), then the response should also include a Vary response header with the value Origin — to indicate to browsers that server responses can differ based on the value of the Origin request header.

Vary: Origin

Handling CORS on the server (Java example)

The following Java code sets CORS response headers. Notice how the code sets the Access-Control-Allow-Origin value to the same value as the Origin request header.

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

public class SimpleCORSFilter implements Filter {

private final Logger log = LoggerFactory.getLogger(SimpleCORSFilter.class);

public SimpleCORSFilter() {"SimpleCORSFilter init");

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {    
    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) res;
    response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));
    response.setHeader("Access-Control-Allow-Credentials", "true");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With, remember-me");
    chain.doFilter(req, res);

public void init(FilterConfig filterConfig) {

public void destroy() {



Specification Status Comment
The definition of 'Access-Control-Allow-Origin' in that specification.
Living Standard Initial definition.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 4Edge Full support 12Firefox Full support 3.5IE Full support 10Opera Full support 12Safari Full support 4WebView Android Full support 2Chrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support 12Safari iOS Full support 3.2Samsung Internet Android Full support Yes


Full support  
Full support

See also