What is HTTP/2 and why you need it.

What is HTTP/2?

HTTP/2 is an internet communication protocol that allow web browsers to simultaneously download several files (html, javascript, css, images etc) that make up a web page. This is called multiplexing. It was introduced in 2015 and helps website pages display much more quickly.

What is the difference between HTTP/1 and HTTP/2?

The main difference is that HTTP/1 allowed files to be downloaded one after the other in series because until recently internet connections were not fast enough (especially on mobile networks) to permit simultaneous downloading. This meant that if a page has a large number of files – especially uncompressed images – then it took longer for the page to display and become interactive and gave a bad user experience.

… and HTTP/3?

HTTP/3 is the most recent version, offering better performance (a simple and faster “handshake”) and has better handling when data packets get lost so the data stream doesn’t jam up. However, at the time of writing (January 2023) most hosting companies don’t offer HTTP/3, so we don’t need to worry about it too much – HTTP/2 is already a big step up.

So, why do I need HTTP/2?

A good user experience is vitally important on today’s internet as a factor that search engines use in deciding how to rank web pages. Page loading speed is therefore a key element in what are now called the Core Web Vitals, a set of 4 indicators that Google has defined as part of their core algorithm.

The perceived quality of your web site will also affect how Google and Bing consider your trustworthiness and will encourage them to crawl, index and rank your pages.

How can I tell if my site has HTTP/2?

Screen shot of the HTTP/2 test tool at Key CDN
Test your HTTP/2 at Key CDN

There are lot of handy tools online to test for HTTP/2, but the one I use regularly is at Key CDN .

How do I get HTTP/2 if I don’t have it?

Most good value modern hosting has HTTP/2 activated, and if yours doesn’t then it probably means that other things about your hosting are not optimal either, so you should change. If your site is hosted on your company’s dedicated server then you’ll need to talk to you server administrator.

More information about HTTP/2