<h2>Description</h2>
<p>The HTTP <code>304 Not Modified</code> client redirection response
code indicates that there is no need to retransmit the requested resources. It is an
implicit redirection to a cached resource. This happens when the request method is
a safe method, such as <code>GET</code> or <code>HEAD</code>,
or when the request is conditional and uses an <code>If-None-Match</code> or an
<code>If-Modified-Since</code> header.</p>
<p>The response must not contain a body and must include the headers that would
have been sent in an equivalent <code>200 OK</code> response:
<code>Cache-Control</code>, <code>Content-Location</code>, <code>Date</code>, <code>ETag</code>, <code>Expires</code>, and <code>Vary</code>.</p>
<aside class="info"><strong>Note:</strong> Many developer tools' network panels
of browsers create extraneous requests leading to 304 responses, so that
access to the local cache is visible to developers.</aside>
<h3>See Also</h3>
<ul>
<li><a href="https://httpwg.org/specs/rfc9110.html#status.304" rel="noopener" target="_blank">Spec</a></li>
<li><a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Modified-Since" rel="noopener" target="_blank">If-Modified-Since</a>, the header that triggers the <code>304 Not Modified</code> response</li>
<li><a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match" rel="noopener" target="_blank">If-None-Match</a>, the header that triggers the <code>304 Not Modified</code> response</li>
<li><a href="https://http.cat/status/204" rel="noopener" target="_blank">204 No Content</a></li>
</ul>
<p><strong>Source:</strong> <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/304" rel="noopener" target="_blank">https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/304</a></p>

3×× Redirection

304 Not Modified

Description

See Also