Testing and using HTTP/2

There’s a handy command-line tool called is-http which is installed using npm as follows:

npm install -g is-http2-cli

Once installed you can check the HTTP/2 status of a web on the command-line:

$ is-http2 www.atomictag.com
✓ HTTP/2 supported by www.atomictag.com
Supported protocols: h2 spdy/3.1 http/1.1

The is-http tool is also useful because it gives you a list of the protocols advertised by the server. As you can see www.cloudflare.com supports HTTP/2, HTTP/1.1 and SPDY/3.1.