--- title: WindowClient slug: Web/API/WindowClient tags: - API - Client - Experimental - Interface - NeedsTranslation - Reference - Service Workers - ServiceWorker - TopicStub - WindowClient translation_of: Web/API/WindowClient --- <p>{{SeeCompatTable}}{{APIRef("Service Workers API")}}</p> <p>The <code>WindowClient</code> interface of the <a href="/en-US/docs/Web/API/ServiceWorker_API">ServiceWorker API</a> represents the scope of a service worker client that is a document in a browser context, controlled by an active worker. The service worker client independently selects and uses a service worker for its own loading and sub-resources.</p> <h2 id="Methods">Methods</h2> <p><em><code>WindowClient</code> inherits methods from its parent interface, {{domxref("Client")}}.</em></p> <dl> <dt>{{domxref("WindowClient.focus()")}}</dt> <dd>Gives user input focus to the current client. </dd> <dt>{{domxref("WindowClient.navigate()")}}</dt> <dd>Loads a specified URL into a controlled client page.</dd> </dl> <h2 id="Properties">Properties</h2> <p><em><code>WindowClient</code> inherits properties from its parent interface, {{domxref("Client")}}.</em></p> <dl> <dt>{{domxref("WindowClient.focused")}} {{readonlyInline}}</dt> <dd>A boolean that indicates whether the current client has focus.</dd> <dt>{{domxref("WindowClient.visibilityState")}} {{readonlyInline}}</dt> <dd>Indicates the visibility of the current client. This value can be one of <code>hidden</code>, <code>visible</code>, <code>prerender</code>, or <code>unloaded</code>.</dd> </dl> <h2 id="Example">Example</h2> <pre class="brush: js">self.addEventListener('notificationclick', function(event) { console.log('On notification click: ', event.notification.tag); event.notification.close(); // This looks to see if the current is already open and // focuses if it is event.waitUntil(clients.matchAll({ type: "window" }).then(function(clientList) { for (var i = 0; i < clientList.length; i++) { var client = clientList[i]; if (client.url == '/' && 'focus' in client) return client.focus(); } if (clients.openWindow) return clients.openWindow('/'); })); });</pre> <h2 id="Specifications">Specifications</h2> <table class="standard-table"> <tbody> <tr> <th scope="col">Specification</th> <th scope="col">Status</th> <th scope="col">Comment</th> </tr> <tr> <td>{{SpecName('Service Workers', '#window-client-interface', 'WindowClient')}}</td> <td>{{Spec2('Service Workers')}}</td> <td>Initial definition</td> </tr> </tbody> </table> <h2 id="Browser_compatibility">Browser compatibility</h2> {{Compat("api.WindowClient")}} <h2 id="See_also">See also</h2> <ul> <li><a href="/en-US/docs/Web/API/ServiceWorker_API/Using_Service_Workers">Using Service Workers</a></li> <li><a href="https://github.com/mdn/sw-test">Service workers basic code example</a></li> <li><a href="https://jakearchibald.github.io/isserviceworkerready/">Is ServiceWorker ready?</a></li> <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise">Promises</a></li> <li><a href="/en-US/docs/Web/Guide/Performance/Using_web_workers">Using web workers</a></li> <li><a href="/en-US/docs/Web/API/Channel_Messaging_API">Channel Messaging API</a></li> </ul>