Performance Best Practices in the HTTP/2 Era

Hypertext Transfer Protocol (HTTP) has been around since 1991, and we haven’t seen a major update since 1999, when HTTP/1.1 was released. During this time a lot of performance best practices have been passed around the web to try and circumvent some of the shortcomings in HTTP/1.1. Sites such as Pingdom and GTmetrix are the de facto when it comes to measuring a site’s performance and for the most part they’re excellent tools. However, some of their recommendations aren’t relevant in the era of HTTP/2.
What’s New?
Let’s take a look at what’s new in HTTP/2 and what that means for performance best practices going into 2017.
Fully Multiplexed
This is arguably the flagship feature of HTTP/2, which fixes one of the biggest problems with HTTP/1.1, namely head-of-line blocking. In layman’s terms it means that only one request can be outstanding on a connection at a time, resulting in latency. This is because the next request is only issued once the response to the current request has been received, resulting in a “queue” of assets to be downloaded from the server.
In an attempt to circumvent this issue a browser may open multiple TCP
Source: https://managewp.org/articles/14221/performance-best-practices-in-the-http-2-era

source https://williechiu40.wordpress.com/2017/01/17/performance-best-practices-in-the-http2-era/