MVC clientCache in web.config not working

Question

i upload my site on a host with iis 8.5 and add below clientCache tag to web.config

<clientCache cacheControlCustom="public" cacheControlMode="UseMaxAge" cacheControlMaxAge="365.00:00:00" />

but my browsers (Firefox, Chrome, IE) doesn't show cache-control with a correct max-age.

response header

Content-Type:text/css
Last-Modified:Wed, 02 Aug 2017 13:24:25 GMT
Accept-Ranges:bytes
ETag:"658df4a892bd31:0"
Server:Microsoft-IIS/8.5
X-Powered-By:ASP.NET
Date:Mon, 28 Aug 2017 16:15:32 GMT
Connection:Keep-Alive
Age:0

request header

User-Agent:Mozilla/5.0 (Windows NT 10.0; …) Gecko/20100101 Firefox/55.0
Accept:text/css;q=0.1
Accept-Language:en-US,en;q=0.5
Accept-Encoding:gzip, deflate
Referer:http://example.com/
Cookie : __RequestVerificationToken=BE9…onId=drzkhe235jaiulgdq10jmbb1
Connection:keep-alive
If-Modified-Since:Wed, 02 Aug 2017 13:24:25 GMT
If-None-Match:"658df4a892bd31:0"
Cache-Control:max-age=0

i read related post but no answer found. thanks for any idea.

Answer 1

Make sure you clear your browser's file cache completely before looking for the Cache-Control header. If the image whose Cache-Control header you are looking for is already being loaded from the cache, then of course you will not see your new header until your browser re-downloads it.