What is Cache-Control: private?

http caching http-headers browser-cache cache-control
user782220 picture user782220 · Oct 16, 2012 · Viewed 121.9k times · Source

When I visit chesseng.herokuapp.com I get a response header that looks like

Cache-Control:private
Connection:keep-alive
Content-Encoding:gzip
Content-Type:text/css
Date:Tue, 16 Oct 2012 06:37:53 GMT
Last-Modified:Tue, 16 Oct 2012 03:13:38 GMT
Status:200 OK
transfer-encoding:chunked
Vary:Accept-Encoding
X-Rack-Cache:miss

and then I refresh the page and get

Cache-Control:private
Connection:keep-alive
Date:Tue, 16 Oct 2012 06:20:49 GMT
Status:304 Not Modified
X-Rack-Cache:miss

so it seems like caching is working. If that works for caching then what is the point of Expires and Cache-Control:max-age. To add to confusion, when I test the page at https://developers.google.com/speed/pagespeed/insights/ it tells me to "Leverage browser caching".

Answer

Dan D. picture Dan D. · Oct 16, 2012 
Cache-Control: private

Indicates that all or part of the response message is intended for a single user and MUST NOT be cached by a shared cache, such as a proxy server.

From RFC2616 section 14.9.1

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