304 Not Modified

The HTTP 304 Not Modified 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 GET or HEAD, or when the request is conditional and uses an If-None-Match or an If-Modified-Since header.

The response must not contain a body and must include the headers that would have been sent in an equivalent 200 OK response: Cache-Control, Content-Location, Date, ETag, Expires, and Vary.

Note: 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.


304 Not Modified


Unknown specification
# status.304

Browser compatibility

BCD tables only load in the browser

Compatibility notes

  • Browser behavior differs if this response erroneously includes a body on persistent connections. See 204 No Content for more detail.

See also