---
title: Last-Modified
slug: Web/HTTP/Headers/Last-Modified
translation_of: Web/HTTP/Headers/Last-Modified
---
<div>{{HTTPSidebar}}</div>

<p>A linha de cabeçalho <strong><code>Last-Modified</code></strong> do cabeçalho de resposta HTTP contém a data e a hora em que o servidor de origem acredita que o recurso foi modificado pela última vez. É usado como um validador para determinar se um recurso recebido ou armazenado é o mesmo. Menos preciso do que um cabeçalho {{HTTPHeader("ETag")}}, é um mecanismo de retorno. Os pedidos condicionais {{HTTPHeader("If-Modified-Since")}} or {{HTTPHeader("If-Unmodified-Since")}} fazem uso deste campo.</p>

<table class="properties">
 <tbody>
  <tr>
   <th scope="row">Header type</th>
   <td>{{Glossary("Response header")}}</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Forbidden header name")}}</th>
   <td>no</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Simple response header", "CORS-safelisted response-header")}}</th>
   <td>yes</td>
  </tr>
 </tbody>
</table>

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

<pre class="syntaxbox">Last-Modified: &lt;day-name&gt;, &lt;day&gt; &lt;month&gt; &lt;year&gt; &lt;hour&gt;:&lt;minute&gt;:&lt;second&gt; GMT
</pre>

<h2 id="Directives">Directives</h2>

<dl>
 <dt>&lt;day-name&gt;</dt>
 <dd>One of "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", or "Sun" (case-sensitive).</dd>
 <dt>&lt;day&gt;</dt>
 <dd>2 digit day number, e.g. "04" or "23".</dd>
 <dt>&lt;month&gt;</dt>
 <dd>One of "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" (case sensitive).</dd>
 <dt>&lt;year&gt;</dt>
 <dd>4 digit year number, e.g. "1990" or "2016".</dd>
 <dt>&lt;hour&gt;</dt>
 <dd>2 digit hour number, e.g. "09" or "23".</dd>
 <dt>&lt;minute&gt;</dt>
 <dd>2 digit minute number, e.g. "04" or "59".</dd>
 <dt>&lt;second&gt;</dt>
 <dd>2 digit second number, e.g. "04" or "59".</dd>
 <dt><code>GMT</code></dt>
 <dd>
 <p>Greenwich Mean Time. HTTP dates are always expressed in GMT, never in local time.</p>
 </dd>
</dl>

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

<pre>Last-Modified: Wed, 21 Oct 2015 07:28:00 GMT
</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", "Last-Modified", "2.2")}}</td>
   <td>Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Compatibilidade com navegadores</h2>

<p>{{Compat("http.headers.Last-Modified")}}</p>

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

<ul>
 <li>{{HTTPHeader("If-Modified-Since")}}</li>
 <li>{{HTTPHeader("If-Unmodified-Since")}}</li>
 <li>{{HTTPHeader("Etag")}}</li>
</ul>