The Fetch API provides an interface for fetching resources (including across the network). It will seem familiar to anyone who has used
XMLHttpRequest, but the new API provides a more powerful and flexible feature set.
Fetch provides a generic definition of
Response objects (and other things involved with network requests). This will allow them to be used wherever they are needed in the future, whether it’s for service workers, Cache API and other similar things that handle or modify requests and responses, or any kind of use case that might require you to generate your own responses programmatically.
It also provides a definition for related concepts such as CORS and the HTTP origin header semantics, supplanting their separate definitions elsewhere.
For making a request and fetching a resource, use the
GlobalFetch.fetch method. It is implemented in multiple interfaces, specifically
WorkerGlobalScope. This makes it available in pretty much any context you might want to fetch resources in.
fetch() method takes one mandatory argument, the path to the resource you want to fetch. It returns a promise that resolves to the
Response to that request, whether it is successful or not. You can also optionally pass in an
init options object as the second argument (see
You can create a request and response directly using the
Response() constructors, but you are unlikely to do this directly. Instead, these are more likely to be created as results of other API actions (for example,
FetchEvent.respondWith from service workers.)
- Contains the
fetch()method used to fetch a resource.
- Represents response/request headers, allowing you to query them and take different actions depending on the results.
- Represents a resource request.
- Represents the response to a request.
- Provides methods relating to the body of the response/request, allowing you to declare what its content type is and how it should be handled.
|Fetch||Living Standard||Initial definition|
|Feature||Chrome||Edge||Firefox (Gecko)||IE||Opera||Safari (WebKit)|
|Basic support||42||14||39 (39)
|Streaming response body||43||14||?||No support||?||No support|
|Feature||Android||Android Webview||Firefox Mobile (Gecko)||IE Phone||Opera Mobile||Safari Mobile||Chrome for Android|
|Basic support||No support||42||(Yes)||No support||No support||10.1||42|
|Streaming response body||No support||43||(Yes)||No support||?||No support||43|
 This API is implemented behind a preference.
 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.