ServiceWorkerRegistration: unregister() method
  The unregister() method of the
  ServiceWorkerRegistration interface unregisters the service worker
  registration and returns a Promise. The promise will resolve to
  false if no registration was found, otherwise it resolves to
  true irrespective of whether unregistration happened or not (it may not
  unregister if someone else just called ServiceWorkerContainer.register()
  with the same scope.) The service worker will finish any ongoing operations before it is
  unregistered.
Note: This feature is available in Web Workers.
Syntax
js
unregister()
Parameters
None.
Return value
  Promise resolves with a boolean indicating whether the service worker has
  unregistered or not.
Examples
The following simple example registers a service worker example, but then immediately unregisters it again:
js
if ("serviceWorker" in navigator) {
  navigator.serviceWorker
    .register("/sw.js", { scope: "/" })
    .then((registration) => {
      // registration worked
      console.log("Registration succeeded.");
      registration.unregister().then((boolean) => {
        // if boolean = true, unregister is successful
      });
    })
    .catch((error) => {
      // registration failed
      console.error(`Registration failed with ${error}`);
    });
}
Specifications
| Specification | 
|---|
| Service Workers # navigator-service-worker-unregister | 
Browser compatibility
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