Aresponse header is anHTTP header that can be used in an HTTP response and that doesn't relate to the content of the message. Response headers, likeAge,Location orServer are used to give a more detailed context of the response.

Not all headers appearing in a response are categorized asresponse headers by the specification. For example, theContent-Type header is arepresentation header indicating the original type of data in the body of the response message (prior to the encoding in theContent-Encoding representation header being applied). However, "conversationally" all headers are usually referred to as response headers in a response message.

The following shows a few response and representation headers after aGET request.

200 OKAccess-Control-Allow-Origin: *Connection: Keep-AliveContent-Encoding: gzipContent-Type: text/html; charset=utf-8Date: Mon, 18 Jul 2016 16:06:00 GMTETag: "c561c68d0ba92bbeb8b0f612a9199f722e3a621a"Keep-Alive: timeout=5, max=997Last-Modified: Mon, 18 Jul 2016 02:36:04 GMTServer: ApacheSet-Cookie: my-key=my value; expires=Mon, 17-Jul-2017 16:06:00 GMT; Max-Age=31449600; Path=/; secureTransfer-Encoding: chunkedVary: Cookie, Accept-EncodingX-Backend-Server: developer2.webapp.scl3.mozilla.comX-Cache-Info: not cacheable; meta data too largeX-kuma-revision: 1085259x-frame-options: DENY

See also

• List of all HTTP headers
• Related glossary terms:
  • Representation header
  • HTTP header
  • Request header