---
title: Server-sent events
slug: Web/API/Server-sent_events
tags:
  - API
  - NeedsTranslation
  - Overview
  - SSE
  - Server-sent events
  - TopicStub
translation_of: Web/API/Server-sent_events
---
<p>{{DefaultAPISidebar("Server Sent Events")}}</p>

<p>Traditionally, a web page has to send a request to the server to receive new data; that is, the page requests data from the server. With server-sent events, it's possible for a server to send new data to a web page at any time, by pushing messages to the web page. These incoming messages can be treated as <em><a href="/en-US/docs/DOM/event">Events</a> + data</em> inside the web page.</p>

<h2 id="Concepts_and_usage">Concepts and usage</h2>

<p>To learn how to use server-sent events, see our article <a href="/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events">Using server-sent events</a>.</p>

<h2 id="Interfaces" name="Interfaces">Interfaces</h2>

<dl>
 <dt>{{domxref("EventSource")}}</dt>
 <dd>Defines all the features that handle connecting to a server, receiving events/data, errors, closing a connection, etc.</dd>
</dl>

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

<ul>
 <li><a href="https://github.com/mdn/dom-examples/tree/master/server-sent-events">Simple SSE demo using PHP</a></li>
</ul>

<h2 id="Specification">Specification</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('HTML WHATWG', '#server-sent-events', 'Server-sent events')}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="See_also" name="See_also">See also</h2>

<h3 id="Tools" name="Tools">Tools</h3>

<ul>
 <li><a href="https://github.com/EventSource/eventsource">EventSource polyfill for Node.js</a></li>
 <li>Remy Sharp’s <a class="link-https" href="https://github.com/remy/polyfills/blob/master/EventSource.js">EventSource polyfill</a></li>
 <li>Yaffle’s <a class="link-https" href="https://github.com/Yaffle/EventSource">EventSource polyfill</a></li>
 <li>Rick Waldron’s <a class="link-https" href="https://github.com/rwldrn/jquery.eventsource">jquery plugin</a></li>
 <li>intercooler.js <a href="http://intercoolerjs.org/docs.html#sse">declarative SSE support</a></li>
</ul>

<h3 id="Related_Topics" name="Related_Topics">Related Topics</h3>

<ul>
 <li><a href="/en-US/docs/AJAX" title="AJAX">AJAX</a></li>
 <li><a href="/en-US/docs/JavaScript" title="JavaScript">JavaScript</a></li>
 <li><a href="/en-US/docs/WebSockets" title="WebSockets">WebSockets</a></li>
</ul>

<h3 id="Other_resources">Other resources</h3>

<ul>
 <li>A <a href="http://hacks.mozilla.org/2011/06/a-wall-powered-by-eventsource-and-server-sent-events/">Twitter like application</a> powered by server-sent events and <a class="link-https" href="https://github.com/mozilla/webowonder-demos/tree/master/demos/friends%20timeline">its code on Github</a>.</li>
 <li><a href="http://dsheiko.com/weblog/html5-and-server-sent-events">HTML5 and Server-sent events</a></li>
 <li><a href="http://rajudasa.blogspot.in/2012/05/html5-server-sent-events-using-aspnet.html">Server-sent events using Asp.Net</a></li>
</ul>