Request.headers

The headers read-only property of the Request interface contains the Headers object associated with the request.

Syntax

var myHeaders = request.headers;

Value

A Headers object.

Example

In the following snippet, we create a new request using the Request.Request() constructor (for an image file in the same directory as the script), then save the request headers in a variable:

var myRequest = new Request('flowers.jpg');
var myHeaders = myRequest.headers; // Headers {}

To add a header to the Headers object we use Headers.append; we then create a new Request along with a 2nd init parameter, passing headers in as an init option:

var myHeaders = new Headers();
myHeaders.append('Content-Type', 'image/jpeg');

var myInit = {
  method: 'GET',
  headers: myHeaders,
  mode: 'cors',
  cache: 'default'
};

var myRequest = new Request('flowers.jpg', myInit);

myContentType = myRequest.headers.get('Content-Type'); // returns 'image/jpeg'

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
headers
40
14
39
No
27
10.1
40
40
39
27
10.3
4.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Request/headers