XMLHttpRequest，但這個新的 API 提供了更強更彈性的功能。
它也提供了諸如 CORS 與 HTTP origin 標頭語意的分散定義，能取代分散的定義。
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.
Experimental fetch controller/signal/observer interfaces
Also known as "cancellable fetch", the following interfaces contain functionality to allow fetch request operations to be observed and controlled during their lifetimes.
- Represents a controller object that allows you to control one or more fetch requests.
- Represents a signal object that allows you to communicate with a fetch request and control it via a
- Represents an observer object that allows you to retrieve information concerning the status of a fetch request.
- Provides a callback function that runs when the fetch request it is assocated with runs. This provides a
FetchObserverobject that can be used to retrieve information concerning the status of a fetch 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|
We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!
|Feature||Chrome||Edge||Firefox (Gecko)||IE||Opera||Safari (WebKit)|
|Basic support||42||14||39 (39)
||43||14||No support||No support||?||No support|
|Feature||Android Webview||Chrome for Android||Edge||Firefox Mobile (Gecko)||IE Phone||Opera Mobile||Safari Mobile|
|Basic support||42||42||(Yes)||(Yes)||No support||No support||10.1|
||43||43||(Yes)||No support||No support||?||No support|
 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 removed.
 Readable streams are currently enabled in Firefox, but hidden behind the