ServiceWorkerRegistration: update() method

Secure context Available in 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

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:

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

Browser compatibility

See also

• Using Service Workers
• Service workers basic code example
• Using web workers