ServiceWorkerRegistration: update() method

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The update() method of the ServiceWorkerRegistration interface attempts to update the service worker. It fetches the worker's script URL, and if the new worker is not byte-by-byte identical to the current worker, it installs the new worker. The fetch of the worker bypasses any browser caches if the previous fetch occurred over 24 hours ago.

Syntax

js
update()

Parameters

None.

Return value

A Promise that resolves with a ServiceWorkerRegistration object.

Examples

The following simple example registers a service worker example then adds an event handler to a button so you can explicitly update the service worker whenever desired:

js
if ("serviceWorker" in navigator) {
  navigator.serviceWorker
    .register("/sw.js", { scope: "/" })
    .then((registration) => {
      // registration worked
      console.log("Registration succeeded.");
      button.onclick = () => {
        registration.update();
      };
    })
    .catch((error) => {
      // registration failed
      console.error(`Registration failed with ${error}`);
    });
}

Specifications

Specification
Service Workers
# service-worker-registration-update

Browser compatibility

BCD tables only load in the browser

See also