Enabling HTTP/2 on NGINX

The now ratified HTTP/2 standard is based on SPDY, an experimental protocol that Google developed internally. As shown in the diagram in the previous recipe, establishing an HTTPS connection can be quite time consuming. With HTTP/1.1, each connection to the web server must follow this process and wait for the handshake to complete.

In HTTP/2, this handshake time is reduced, but more importantly the requests are multiplexed over a single TCP connection. This means that the handshake only has to occur once, significantly reducing the latency of a site for the end user. In fact, it means that an HTTP/2-based site can actually be quicker than a standard HTTP-based one.

There are a number of other benefits that HTTP/2 also provides, such as header compression, a new binary protocol, and a server-based push. All of these further increase the efficiency of HTTP/2, yet it also remains backwards compatible with HTTP/1.1:

All modern browsers (as shown in the preceding figure) support HTTP/2 natively, so it's ready to deploy in production. NGINX officially supported HTTP/2 starting with version 1.9.5.