Revision 1104593 of 304 Not Modified

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

<p>The HTTP <code><strong>304</strong></code><strong><code> Not Modified</code></strong> client redirection response code indicates that their is no need to retransmit the requests resources. It is an implicit redirection to a cached resources. This happens when the request method is {{glossary("safe")}}, like a {{HTTPMethod("GET")}} or a {{HTTPMethod("Head")}} and the request is conditional and use a {{HTTPHeader("If-None-Match")}} or a {{HTTPHeader("If-Modified-Since")}} headers.</p>

<div class="note">
<p>Many developer tools network panels of browsers create extraneous requests leading to <code>304</code> responses so that accesses to the local cache are visible to the developers.</p>
</div>

<h2 id="Status">Status</h2>

<pre class="syntaxbox">
304 Not Modified</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("7232", "304 Not Modified" , "4.1")}}</td>
   <td>Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests</td>
  </tr>
 </tbody>
</table>

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

<p class="hidden">The compatibility table in this page is generated from structured data. If you’d like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data/README.md">https://github.com/mdn/browser-compat-data/README.md</a> and send us a pull request.</p>

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

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

<ul>
 <li>{{HTTPHeader("If-Modified-Since")}}</li>
 <li>{{HTTPHeader("If-None-Match")}}</li>
</ul>