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 safe, like a GET or a HEAD request, or when the request is conditional and uses a If-None-Match or a If-Modified-Since header.

The equivalent 200 OK response would have included the headers 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.

Status

304 Not Modified

Specifications

Specification
Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests (HTTP/1.1)
# 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