Chrome doesn't send “If-Modified-Since”

Question

I want browsers to always add (except first time) \"If-Modified-Since\" request header to avoid unnecessary traffic.

Response headers are:

Accept-Ranges:         


        

Answer 1

I had the same problem, in Chrome all requests were always status code 200, in other browsers 304.

It turned out I had the disable cache (while DevTools is open) checked in on Devtools - Settings - General page..:)