index.md

---

title: BackgroundFetchManager.fetch()
slug: Web/API/BackgroundFetchManager/fetch
page-type: web-api-instance-method
status:
  - experimental
browser-compat: api.BackgroundFetchManager.fetch

---

{{APIRef("Background Fetch API")}}{{SeeCompatTable}}

The fetch() method of the {{domxref("BackgroundFetchManager")}} interface returns a {{jsxref("Promise")}} that resolves with a {{domxref("BackgroundFetchRegistration")}} object for a supplied array of URLs and {{domxref("Request")}} objects.

Syntax

fetch(id, requests)
fetch(id, requests, options)

Parameters

• id

  • : A developer-defined identifier that can be passed to the other methods to retrieve a {{domxref("backgroundFetchRegistration")}}.

• requests

  • : A {{domxref("RequestInfo")}} object or an array of such objects.

• options {{optional_inline}}

  • : A {{domxref("BackgroundFetchOptions")}} object.

Return value

A {{jsxref("Promise")}} that resolves with a {{domxref("BackgroundFetchRegistration")}} object.

Exceptions

• {{jsxref("TypeError")}}

  • : Raised if no request is provided, if the mode of a request is 'no-cors', if no service worker is present, a request already exists with the requested id, or the request fails.

• AbortError {{domxref("DOMException")}}

  • : Indicates that the fetch was aborted.

• NotAllowedError {{domxref("DOMException")}}

  • : Indicates that user permission has not been granted to make background fetches.

Examples

The following examples shows how to use fetch() to create a {{domxref("BackgroundFetchRegistration")}}. With an active {{domxref('ServiceWorker', 'service worker')}}, use the {{domxref('ServiceWorkerRegistration.backgroundFetch')}} property to access the BackgroundFetchManager object and call its fetch() method.

navigator.serviceWorker.ready.then(async (swReg) => {
  const bgFetch = await swReg.backgroundFetch.fetch(
    "my-fetch",
    ["/ep-5.mp3", "ep-5-artwork.jpg"],
    {
      title: "Episode 5: Interesting things.",
      icons: [
        {
          sizes: "300x300",
          src: "/ep-5-icon.png",
          type: "image/png",
        },
      ],
      downloadTotal: 60 * 1024 * 1024,
    }
  );
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}