Revision 1086183 of HEAD

<div>{{HTTPSidebar}}</div>

<p>The <code>HEAD</code> method requests the headers that would be returned if the specified resource would be done with a {{HTTPMethod("GET")}}. Such a request can be done before deciding to download a large resource to save bandwidth.</p>

<p>A response to a <code>HEAD</code> method should not have a body. If so, it must be ignored. Even so, {{glossary("Entity header", "entity headers")}} describing the content of body, like {{HTTPHeader("Content-Length")}} may be included in the response. They don't relate to the body of the <code>HEAD</code> response, that should be empty, but to the body a similar request with the {{HTTPMethod("GET")}} method would have returned in its response.</p>

<p>If the result of a <code>HEAD</code> requests shows that a resource cached after a {{HTTPMethod("GET")}} request is now outdate, the cache is invalidated, even if no <code>GET</code> method has been done.</p>

<table class="properties">
 <tbody>
  <tr>
   <th scope="row">Request has body</th>
   <td>No</td>
  </tr>
  <tr>
   <th scope="row">Successful response has body</th>
   <td>No</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Safe")}}</th>
   <td>Yes</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Idempotent")}}</th>
   <td>Yes</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Cacheable")}}</th>
   <td>Yes</td>
  </tr>
  <tr>
   <th scope="row">Allowed in <a href="/en-US/docs/Web/Guide/HTML/Forms">HTML forms</a></th>
   <td>No</td>
  </tr>
 </tbody>
</table>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox">
HEAD /index.html
</pre>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Title</th>
  </tr>
  <tr>
   <td>{{RFC("7231")}}</td>
   <td>Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content</td>
  </tr>
 </tbody>
</table>

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

<p class="hidden">To contribute to this compatibility data, please write a pull request against this file: <a href="https://github.com/mdn/browser-compat-data/blob/master/http/methods.json">https://github.com/mdn/browser-compat-data/blob/master/http/methods.json</a>.</p>

<p>{{Compat}}</p>

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

<ul>
 <li>{{HTTPMethod("Get")}}</li>
</ul>