Chrome browser is not sending if-modified-since header to server

Question

I have these headers being sent to the client by the server:

Cache-Control:private
Connection:keep-alive
Content-Encoding:gzip
Content-Type:text/html
Date:Su         


        

Answer 1

In addition (https://stackoverflow.com/a/14899869/362780):

F12 > Settings > General > Disable cache (while DevTools is open) -> uncheck this...