You have installed the latest nginx version on your server to be able to offer HTTP2 to your visitors, but you have no idea how to check if HTTP2 is working?
There are two ways to check if your HTTP2 configuration is working.
Firefox browser plugin
The blue bolt means that your site is using HTTP2. If the bolt is green, the site is using the deprecated SPDY protocol.
Another way is to check the server logs. If you visit your site with one of the latest browser versions, you should see something like this:
XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX - - [22/Apr/2016:08:09:51 +0200] "GET / HTTP/2.0" 200 10599 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.112 Safari/537.36"
As you can see, the command executed is “GET / HTTP/2.0”, so this request was a HTTP2 request.