What is the Difference between HTTP 1.2 and HTTP 2.0 versions? why should I care?

Well, this question is very basic, but many of us don't know what is the exact purpose, and why the name has changed and what might be the difference.

Since, we all know HTTP is protocol that is widely used over internet, HTTP 1.1 has turned into a protocol used for virtually everything on the Internet. HTTP 1.1 version came to picture in 1997, since then the protocol was unchanged, but IETF(Internet Engineering Task Force) revised the protcol and released a newer version of HTTP i.e. HTTP 2.0 in the year 2015.

So what is the difference, There are many advancement and the new feature was implemented in HTTP 2.0 , since HTTP 1.1 "practically" only allows one outstanding request per TCP connection. But with HTTP 2.0 we can have multiple request at a time.

If you can see in example below, A web page comprising of two files:

1) style.css (to enhance the UI display)

2) Script.js (to make interactive web page)

When we use http 1.1 version, if you request web page at a one time only 1 file is getting loaded on your UI, but with HTTP 2.0 both file will get loaded.

This is Multiplexing multiple requests over a single TCP connection an advantage out of many advantages in HTTP 2.0 together with HTTP headers compression, priority and more intelligent packet streaming management. This results in reduced latency and accelerates content download on modern web pages.

 Why should I care?

This is important while Testing your web page performance and the speed of content delivery. 

Here is Video that will help you to understand how much the Performance is improved in HTTP 2.0, it is beneficial for organization websites who deal with millions of transaction in second, have a quick look:

HTTP/2 vs. HTTP/1.1: A Performance Analysis

You can get to what version of http your website is running on by inspecting network tab of your browser developer tool by F12

In Addition for a quick check of your website supports the http 2.0 or not, you can add a google chrome extension name

you can check on this website as well:

Check Website Supports http 2.0 or not here

Can I use HTTP/2 now?

In browsers, HTTP/2 is supported by the most current releases of Edge, Safari, Firefox and Chrome. Other browsers based upon Blink will also support HTTP/2 (e.g., Opera and Yandex Browser).

Will HTTP/2 replace HTTP/1.x?

The goal of the Working Group is that typical uses of HTTP/1.x can use HTTP/2 and see some benefit. Having said that, we can’t force the world to migrate, and because of the way that people deploy proxies and servers, HTTP/1.x is likely to still be in use for quite some time.

Will there be a HTTP/3?

If the negotiation mechanism introduced by HTTP/2 works well, it should be possible to support new versions of HTTP much more easily than in the past.