HTTP/2

In the position of HTTP/2 being the evolutionary version of this SPDY, specifications were advanced by IETF (Internet Engineering Task Force) in May 2015 to achieve RFC conversion.

HTTP/2 has no effect unless both server side and client side support HTTP/2. However, even if the client side is incompatible with HTTP/2, communication can not be disabled, but communication can be performed using conventional HTTP/1.1 .

Whether the web site is compatible with HTTP/2 can be easily checked by using the browser plugin.

"HTTP/2 and SPDY indicator" plug-in

My site (https://hhoshina.info) has already corresponded to HTTP/2.