The magic ingredients in mobile web performance

Optimising your site's mobile web performance can improve your user experience and could lead to increased sales.

No doubt, the internet is fueling economic growth around the world. According to Statista, in 2016, the share of the internet economy in the GDP of the developing countries reached around 5.5 percent. And though there are more than a million tips out there about how to get your piece of the pie, there is no such thing as a universal recipe. Success in the digital economy hinges on many ingredients but there is one you can’t afford to miss: web performance.   

Web performance is priceless as it only takes a split second to lose a customer. Impatient visitors penalise slow websites by leaving; some never to return. Ten years ago, Amazon discovered during A/B tests that every 100ms of latency cost them one percent in sales. If anything people have become more impatient over the last 10 years. But getting performance right is easier said than done. Two recent developments put web performance under particular stress: mobile usage explosion and growing page size. 

First let’s look at “proliferation of mobile.” Cisco’s Visual Networking Index predicts that by 2020, smartphone traffic will even surpass PC traffic. With this growth comes pain. Ubiquitous information access has sped up our lives and made us impatient. Research (“Speed is key: optimize your mobile experience) from Google revealed that “when your site or app is clumsy or slow, 29% of smartphone users will immediately switch to another site or app (...). In fact, of those who switch, 70% do so because of lagging load times.” The analyst house Forrester concludes in the summary of its report “The Top Technologies To Cure Mobile Performance”: “Digital experiences on mobile connections suffer from performance issues, and impatient users compound the challenges that slower, intermittent mobile connections raise.”   

This problem gets worse when we factor in the second development -  growing page size.  Since the beginning of the internet page size has increased dramatically. According to research from software engineer Ronan Cremin, the average web page weighs more or less the same as the computer game Doom, with all its bells and whistles. To be more concrete, the HTTP Archive shows that in November 2016 an average web page weighed about 2,509KB. Images comprised the largest portion at 1,624KB. This is very high considering that in 2010 the average page size was less than half that size (about 700KB). In 1995 the average page size was a mere 14KB. 

When businesses develop websites nowadays, there is no longer any choice but to optimise for mobile. This is particularly true for the content-heavy sites used in eCommerce, retail, media or any sharing economy business. One feature most sites already use is mobile device detection. It ensures an optimal user experience on all devices. It accurately detects the characteristics of every mobile and web connected device and dynamically adapts the website content based on the device capabilities. However, mobile device detection alone is not enough - especially for content heavy sites. If their content doesn’t load fast enough on the mobile, they will truly be “Doomed”.   

Intelligent caching technology improves perceived performance dramatically 

Intelligent caching technology is the magic ingredient that ensures websites load fast and can cope with major traffic peaks - whether on mobile or desktop. A cache works just like an ordinary web server, intercepting all web requests before they reach the company’s server. The cache answers and delivers requests in microseconds: two orders of magnitude faster than the average origin server. The company server doesn’t have to reproduce multiple impressions of the same page and the next user can view the page without experiencing a delay. By doing so, it can serve up to tens of thousands of consecutive requests per second, speeding up website performance and reducing server load. The end user can perceive improvements of up to 1,000 percent. 

The icing on the cake - much faster mobile page loads 

Businesses wanting to optimize websites for mobile can create even more magic using modern caching features. Many websites display personalised content for every individual user, for example web catalogues or news pages based on the interest or behaviour. If one of these page elements needs to be updated and changed, the entire cache doesn’t work anymore and you need to rebuild it for all sites that include this element.   

Technologies such as Edge Side Includes (ESI) have solved half of this issue. With ESI you just need to update that single element and all the other pages automatically receive the updated content. However, the update can be quite slow as the web page fetches the elements and loads them one after another. 

A newer and faster way to load elements offers parallel ESI. It immediately seeks out and fetches the needed fragments in parallel - all at the same time. As a result, web pages load significantly faster, which is especially important when delivering content to mobile users.   

Faster page assembly for the modern consumer 

Another feature some modern caching solutions offer is the ability to improve the page assembly process. Most modern website content is assembled in a user’s browser, which can take, in the slowest instances, tens of seconds. Templating languages are a ‘secret sauce’ for assembling pages using the bits and pieces already stored in the cache, eliminating that seconds-long process and delivering pages in milliseconds. These split-second differences might not sound like much, but they make a huge difference to the user experience.   

 Interestingly, as Colin Bendell, Director at Akamai’s CTO Office, pointed out at a recent conference, TLS encryption also helps to gain small performance wins. Inside the cellular networks, unencrypted traffic is slowed down whereas TLS encrypted traffic is queued up and put through faster. 

As the percentage of consumers accessing the web via mobile devices continues to climb, increasing the speed of mobile content delivery should be a top priority for businesses, especially those with content-heavy sites. Taking shortcuts and not fully vetting technical solutions for a mobile website risks damaging the brand and alienating customers. Having intelligent caching features in place to accelerate the mobile web prevents this from happening. 

These are just a few ingredients that will help you serve up the best possible mobile web performance and an unbeatable user experience. Chances are high that you’ll enjoy a bigger piece of the pie as well. 

Image Credit: Varnish Software