New advanced technologies, such as HTTP/2 multiplexing, as well as new content, have contributed to the rapid development of the Web and it is also facing the increasing demands of Internet users. Conventional websites are now facing competition that exceeds them both in terms of usability and ergonomics for users. The loading time as well as the data transfer play a crucial role in the palliation of these failures and aims at a fast and easy use of modern Internet sites. In this sense, the existence of a new extension of the HTTP/1.1 protocol, HTTP/2, whose aim is to reduce load times is not surprising.

But what is HTTP?

Loading a website requires many hierarchically ordered protocols that regulate the sending and transfer of data. The Hypertext Transfer Protocol, better known by its abbreviation HTTP, is a higher-level protocol, also called an application layer. This transfer protocol allows the communication of applications (browsers for example) with the respective Web servers, on which the sites in question are hosted. The HTTP protocol transmits to the browser the hypertext of the site which is then transformed into texts, images, and videos.

From a technical point of view, each communication unit is made up of two parts: the HTTP header (or HTTP header) as well as the body of the message. The header provides all the relevant information on how the body of the message, which contains usage data, should be interpreted.

In addition to the two main pillars of the World Wide Web, the URL, and the HTML, the development of the HTTP protocol began in 1989 at the premises of the European Organization for Nuclear Research (CERN) in Switzerland. The first was published as RFC 1945 (Request for Comments) as HTTP/1.0. In June 1999, the first version was replaced by HTTP/1.1 which is still used today. Its official successor HTTP/2 was adopted in May 2015 as RFC 7540 and is expected to revolutionize data transfer in the World Wide Web.

The development of HTTP/2

Google presented in 2009 its alternative to HTTP/1.1 called SPDY. The biggest flaw with this older version of HTTP was that it slowed down new modern sites with complex interfaces. This was explained by the fact that during the use of HTTP/1.1, for each data, a new TCP/IP connection had to be created. Thanks to SPDY, Google has solved the problem by multiplexing their transfers.

Thus, multiple documents of your choice can be sent over a TCP/IP connection. Thanks to a draft based on Google’s SPDY protocol, the Internet Engineering Task Force (abbreviated IETF, literally Internet Engineering Detachment) started its work on HTTP/2 in 2012. Since the implementation of SPDY presented to the era of many shortcomings and particularly in terms of security, major modifications had to be made, which led to a result fundamentally different from the initial protocol.

Here are the new features offered by HTTP/2

The particularity of the HTTP/1.1 protocol has already been mentioned: in order to transfer various elements such as static files (images, JavaScript, CSS) to the browser, a separate TCP/IP connection must be opened and closed. Like its predecessor SPDY, HTTP/2 uses the multiplexing mechanism so that the entire site can be loaded via a single connection. In addition, the server is now able to transfer predictable results data to the client without the client requesting it (push server).

With HTTP/2, data packets are sent in order of priority, the elements responsible for building the page first, for example. Unlike HTTP/1.1, the HTTP/2 header is sent in compressed form, removing unnecessary information. Another new feature is the use of binary codes (instead of text files) during communication, which facilitates communication and prevents errors.

HTTP/2: browser support

Many changes have taken place since the release of the HTTP/2 protocol. There are now many browsers and servers that support it. Mozilla Firefox, for example, has implemented the protocol since version 36 in February 2015. With regard to earlier versions, it turns out that only websites with HTTP/2 via TLS (ie the encrypted version of the transmission protocol ) are downloaded.

Almost 80% of browsers support HTTP/2. Opera Mini, Blackberry Browser, IE Mobile and UC Browser for Android have notably implemented HTTP/2 in their new browser versions (Status: March 2017). To find out more, you can consult the figures presented by Caniuse.

The number of websites that already use the new transmission protocol is minimal compared to the few browsers that support it. However, this number increased considerably in one year, from the end of September 2016 to almost 10%. In March 2017, 12.7% of all websites still used HTTP/2. For more information on the current use of the protocol, you can consult the statistics. So far, only highly reputable administrators like Google or Twitter have switched to the HTTP/2 protocol. Considering the advantages and the ever increasing support by the main browsers, the wide use of HTTP/2 is however only a question of time.

Thanks to the high-level SiteGround hosting packages, you can have the HTTP/2 protocol for your web projects and benefit from an SSL certificate for optimal protection.

The following table illustrates which browsers are compatible with HTTP/2:

And after that?

Switching to HTTP/2 is not mandatory, but can have some advantages. In addition, it should be noted that since the end of 2014 SSL/TLS encryption has been an important factor in the ranking on Google’s SERPs. It, therefore, influences natural referencing. If you have been considering certifying your own website, we recommend that you switch directly to the HTTP/2 protocol via TLS.

The use of HTTP/2 can only be positive for your site in terms of SEO. First, it promotes a short loading time and therefore a good evaluation by Google. On the other hand, HTTP/2 guarantees that the loading time of your site is less than two seconds, the threshold set by Google from which a URL address is rarely indexed. Thanks to HTTP/2, your website will be indexed regularly by Google and its new content integrated faster in the index.

To verify that your current website is running under HTTP/2, you can check that easily in KeyCDN.

Do you want your site to be more secure? Check here to learn more about SSL certificates and how they can improve the reliability of your site.