Web/API/Headers/get

The get() method of the Headers interface returns a byte string of all the values of a header within a Headers object with a given name. If the requested header doesn't exist in the Headers object, it returns null.

For security reasons, some headers can only be controlled by the user agent. These headers include the forbidden header names and forbidden response header names.

Syntax

myHeaders.get(name);

Parameters

name: The name of the HTTP header whose values you want to retrieve from the Headers object. If the given name is not the name of an HTTP header, this method throws a TypeError. The name is case-insensitive.

Returns

A ByteString sequence representing the values of the retrieved header or null if this header is not set.

Example

Creating an empty Headers object is simple:

var myHeaders = new Headers(); // Currently empty
myHeaders.get('Not-Set'); // Returns null

You could add a header to this using Headers.append, then retrieve it using get():

myHeaders.append('Content-Type', 'image/jpeg');
myHeaders.get('Content-Type'); // Returns "image/jpeg"

If the header has multiple values associated with it, the byte string will contain all the values, in the order they were added to the Headers object:

myHeaders.append('Accept-Encoding', 'deflate');
myHeaders.append('Accept-Encoding', 'gzip');
myHeaders.get('Accept-Encoding'); // Returns "deflate,gzip"

Note: Headers.getAll used to have this functionality, with Headers.get returning only the first value added to the Headers object. The latest spec has removed getAll(), and updated get() to return all values.

Specifications

Specification	Status	Comment
FetchThe definition of 'get()' in that specification.	Living Standard

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`get` Experimental'	Chrome Full support 42 Full support 42 Full support 41 Disabled' Disabled' From version 41: this feature is behind the `Experimental Web Platform Features` preference. To change preferences in Chrome, visit chrome://flags.	Edge Full support 14	Firefox Full support 52 Notes' Full support 52 Notes' Notes' Prior to Firefox 52, `get()` only returned the first value in the specified header, with `getAll()` returning all values. From 52 onwards, `get()` now returns all values and `getAll()` has been deleted. Full support 39 Full support 34 Disabled' Disabled' From version 34: this feature is behind the `dom.fetch.enabled` preference. To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 29 Full support 29 Full support 28 Disabled' Disabled' From version 28: this feature is behind the `Experimental Web Platform Features` preference.	Safari Full support 10.1	WebView Android Full support 42	Chrome Android Full support 42 Full support 42 Full support 41 Disabled' Disabled' From version 41: this feature is behind the `Experimental Web Platform Features` preference. To change preferences in Chrome, visit chrome://flags.	Firefox Android No support No	Opera Android Full support 29 Full support 29 Full support 28 Disabled' Disabled' From version 28: this feature is behind the `Experimental Web Platform Features` preference.	Safari iOS No support No	Samsung Internet Android Full support 4.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.
See implementation notes.': See implementation notes.
User must explicitly enable this feature.': User must explicitly enable this feature.