---
title: Clients
slug: Web/API/Clients
tags:
  - API
  - Clients
  - Experimental
  - Interface
  - NeedsTranslation
  - Reference
  - Service Workers
  - Service worker API
  - ServiceWorker
  - TopicStub
  - Workers
translation_of: Web/API/Clients
---
<p>{{SeeCompatTable}}{{APIRef("Service Workers API")}}</p>

<p><span class="seoSummary">The <code>Clients</code> interface provides access to {{domxref("Client")}} objects. Access it via <code>{{domxref("ServiceWorkerGlobalScope", "self")}}.clients</code> within a <a href="/en-US/docs/Web/API/ServiceWorker_API">service worker</a>.</span></p>

<h2 id="Methods">Methods</h2>

<dl>
 <dt>{{domxref("Clients.get()")}}</dt>
 <dd>Returns a {{jsxref("Promise")}} for a {{domxref("Client")}} matching a given {{domxref("Client.id", "id")}}.</dd>
 <dt>{{domxref("Clients.matchAll()")}}</dt>
 <dd>Returns a {{jsxref("Promise")}} for an array of {{domxref("Client")}} objects. An options argument allows you to control the types of clients returned. </dd>
 <dt>{{domxref("Clients.openWindow()")}}</dt>
 <dd>Opens a new browser window for a given url and returns a {{jsxref("Promise")}} for the new {{domxref("WindowClient")}}.</dd>
 <dt>{{domxref("Clients.claim()")}}</dt>
 <dd>Allows an active service worker to set itself as the {{domxref("ServiceWorkerContainer.controller", "controller")}} for all clients within its {{domxref("ServiceWorkerRegistration.scope", "scope")}}. </dd>
</dl>

<h2 id="Examples">Examples</h2>

<p>The following example shows an existing chat window or creates a new one when the user clicks a notification.</p>

<pre class="brush: js">addEventListener('notificationclick', event =&gt; {
  event.waitUntil(async function() {
    const allClients = await clients.matchAll({
      includeUncontrolled: true
    });

    let chatClient;

    // Let's see if we already have a chat window open:
    for (const client of allClients) {
      const url = new URL(client.url);

      if (url.pathname == '/chat/') {
        // Excellent, let's use it!
        client.focus();
        chatClient = client;
        break;
      }
    }

    // If we didn't find an existing chat window,
    // open a new one:
    if (!chatClient) {
      chatClient = await clients.openWindow('/chat/');
    }

    // Message the client:
    chatClient.postMessage("New chat messages!");
  }());
});
</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', '#clients', 'Clients')}}</td>
   <td>{{Spec2('Service Workers')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<div>


<p>{{Compat("api.Clients")}}</p>
</div>

<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://jakearchibald.github.io/isserviceworkerready/">Is ServiceWorker ready?</a></li>
 <li>{{jsxref("Promise")}}</li>
</ul>