---
title: WebSockets
slug: WebSockets
tags:
  - References
  - WebSockets
translation_of: Web/API/WebSockets_API
---
<p>I WebSockets sono una tecnologia avanzata che rende possibile aprire una sessione di comunicazione interattiva tra il browser dell'utente e un server. Con questa API si possono mandare messaggi al server e ricevere risposte event-driven senza doverle richiedere al server.</p>

<div class="cleared row topicpage-table">
<div class="section">
<h2 class="Documentation" id="Documentation" name="Documentation">Documentazione</h2>

<dl>
 <dt><a href="/en-US/docs/WebSockets/Writing_WebSocket_client_applications" title="WebSockets/Writing WebSocket client applications">Scrivere applicazioni WebSocket lato client</a></dt>
 <dd>Un tutorial per scrivere applicazioni WebSocket da eseguire nel browser.</dd>
 <dt><a href="/en-US/docs/WebSockets/WebSockets_reference" title="WebSockets/WebSockets reference">WebSockets reference</a></dt>
 <dd>Informazioni dettagliate sulla API lato client.</dd>
 <dt><a href="/en-US/docs/WebSockets/Writing_WebSocket_servers" title="WebSockets/Writing WebSocket servers">(TBD) Writing WebSocket servers</a></dt>
 <dd>Una guida per scrivere applicazioni lato server che gestiscano il protocollo WebSocket.</dd>
</dl>

<p><span class="alllinks"><a href="/en-US/docs/tag/WebSockets" title="tag/WebSockets">Visualizza tutti</a></span></p>
</div>

<div class="section">
<h2 class="Tools" id="Tools" name="Tools">Strumenti</h2>

<ul>
 <li><a class="external" href="http://socket.io" title="http://socket.io/">Socket.IO</a>: Una potente API cross-platform per WebSocket e <a class="external" href="http://nodejs.org" title="http://nodejs.org/">Node.js</a>.</li>
 <li><a class="link-https" href="https://github.com/Worlize/WebSocket-Node" title="https://github.com/Worlize/WebSocket-Node">WebSocket-Node</a>: Un'implementazione lato server dell'API di Websocket per <a class="external" href="http://nodejs.org" title="http://nodejs.org/">Node.js</a>.</li>
 <li><a href="http://ajf.me/websocket/#libs" title="http://websocket.us/#libs">Una lista più completa di framework e librerie</a></li>
</ul>

<h2 class="Related_Topics" id="Related_Topics" name="Related_Topics">Argomenti correlati</h2>

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

<h2 id="Vedi_anche">Vedi anche</h2>

<ul>
 <li><a class="external" href="http://tools.ietf.org/html/rfc6455">RFC 6455 - The WebSocket Protocol</a></li>
 <li><a class="external" href="http://www.w3.org/TR/websockets/">WebSocket API Specification</a></li>
 <li><a href="/en-US/docs/Server-sent_events" title="Server-sent_events">Server-Sent Events</a></li>
 <li><a class="external" href="http://websocket.us/">WebSocket.us</a> - a community-run, not-for-profit site about WebSocket</li>
</ul>

<h2 id="Compatibilità_tra_browser">Compatibilità tra browser</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Version -76 support {{obsolete_inline}}</td>
   <td>6</td>
   <td>{{CompatGeckoDesktop("2.0")}}</td>
   <td>{{CompatNo}}</td>
   <td>11.00 (disabled)</td>
   <td>5.0.1</td>
  </tr>
  <tr>
   <td>Protocol version 7 support {{obsolete_inline}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatGeckoDesktop("6.0")}}<br>
    {{property_prefix("Moz")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
  </tr>
  <tr>
   <td>Protocol version 10 support {{obsolete_inline}}</td>
   <td>14</td>
   <td>{{CompatGeckoDesktop("7.0")}}<br>
    {{property_prefix("Moz")}}</td>
   <td>HTML5 Labs</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td>Standard - RFC 6455 Support</td>
   <td>16</td>
   <td>{{CompatGeckoDesktop("11.0")}}</td>
   <td>10</td>
   <td>12.10</td>
   <td>6.0</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Version -76 support {{obsolete_inline}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td>Protocol version 7 support {{obsolete_inline}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td>Protocol version 8 support (IETF draft 10) {{obsolete_inline}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoMobile("7.0")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td>Standard - RFC 6455 Support</td>
   <td>16 (Chrome)</td>
   <td>{{CompatGeckoDesktop("11.0")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>12.10</td>
   <td>6.0</td>
  </tr>
 </tbody>
</table>
</div>

<h3 id="Gecko_notes">Gecko notes</h3>

<p>WebSockets support in Firefox is continuing to track the evolving WebSocket specification. Firefox 6 implements version 7 of the underlying protocol, while Firefox 7 implements version 8 (as specified by IETF draft 10). Firefox mobile received WebSocket support in Firefox mobile 7.0.</p>

<h4 id="Gecko_6.0">Gecko 6.0</h4>

<p>Prior to Gecko 6.0 {{geckoRelease("6.0")}}, there was, incorrectly, a <code>WebSocket</code> object that some sites were thinking implied that <code>WebSocket</code> services were not prefixed; this object has been renamed to <code>MozWebSocket</code>.</p>

<h4 id="Gecko_7.0">Gecko 7.0</h4>

<p>Starting in Gecko 7.0 {{geckoRelease("7.0")}}, the <code>network.websocket.max-connections</code> preference is used to determine the maximum number of WebSocket connections that can be open at a time. The default value is 200.</p>

<h4 id="Gecko_8.0">Gecko 8.0</h4>

<p>Starting in Gecko 8.0 {{geckoRelease("8.0")}}, the deflate-stream extension to the WebSocket protocol has been disabled, since it's been deprecated from the specification drafts. This resolves incompatibilities with some sites.</p>

<h4 id="Gecko_11.0">Gecko 11.0</h4>

<p>Prior to Gecko 11.0, both incoming and outgoing messages were limited to 16 MB in size. They may now be up to 2 GB in size. Note, however, that memory limitations (especially on mobile devices) make that a theoretical maximum, not a practical one. In reality, transfers of that size will fail on devices that don't have enough memory.</p>

<p>Additionally, ArrayBuffer send and receive support for binary data has been implemented.</p>

<p>Starting in Gecko 11.0, the WebSocket API is no longer prefixed.</p>

<div class="warning"><strong>Warning:</strong> Among other things, a key reason WebSockets was disabled by default in Firefox 4 and 5 is the discovery of a <a class="external" href="http://www.ietf.org/mail-archive/web/hybi/current/msg04744.html" title="http://www.ietf.org/mail-archive/web/hybi/current/msg04744.html">security issue in the protocol's design</a>. This was fixed in Firefox 6 by implementing a newer version of the protocol that corrects the problem.</div>

<div>{{HTML5ArticleTOC}}</div>