What is this HTTP2 you speak of

Posted on by jordanhaines

In the past year the talk of HTTP2 has gone hand in hand with the talk that all sites should have a SSL certificate and be using HTTPS. This was mainly because Google has started saying that going forward sites that use HTTPS will get a ranking boast, This is all because Google is pushing for a more secure web. Something we can all get behind, But to explain what HTTP 2 is I think it is best to start off with what we have now HTTP (Hypertext Transfer Protocol).

HTTP explained

HTTP is the current protocol we have now, it has been around since the start of the web and the version of HTTP we have now HTTP 1.1 came out in 1999.

Websites in 1999 looked a lot different from the websites we have today. There was of course no responsive design, There was very little CSS and JS. A website back in 1999 was just plain HTML and some images, The size of a website was also a lot smaller.

When you request a website from your browser in the current HTTP protocol, each resource which by this I mean, every image file, every CSS file, every JS file is requested 1 at a time. This means that if you have a large image file this will slow down the loading of the other files which in turn slows down the loading of the website.

Websites over the years have gotten bigger and now need to do a lot more which means that the old HTTP protocol is not very efficient in delivering websites.

HTTP 2 explained

In 2009 Google posted about a research project they had been working on named SPDY (Speedy). SPDY was not a new protocol is just modified the way existing HTTP requests and responses are sent.

SPDY addressed some of HTTP short comings with modern websites, These where:

  • allow multiplexing – This means that multiply files can be downloaded at the same time which will in turn speed up your website;
  • allow browsers to prioritize assets so that resources vital to the display of a page could be sent by the server first;
  • compress and reduce HTTP headers – This speeds up how fast your website is downloaded to the users browser.
  • implement server push, whereby a server can push vital resources to the browser before being asked for them.

SPDY was successful and became HTTP 2 which is built upon this success and in February 2015 the final spec was approved with browser support a year on being excellent , so you can start using it right now. Please remember that HTTP2 is browser and server side, This means that it is best to check with your hosting provider that they support HTTP2.

http2 diagram

Google Benefits

HTTP2 is what all websites should be using and this fact is backed up with Google pushing all sites to become faster and use HTTPS. If your site uses HTTPS today then you will more then likely be using HTTP2, To test this you can use the following website: https://tools.keycdn.com/http2-test

So what you waiting for, Go us HTTP2 now and speed up your website.

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