Slow Websites Kill Conversions and Lose Sales

Website loading times are an important part of how users experience your business and brand. Slow websites will see much higher bounce rates and naturally lower conversions (sales). The average user will not wait longer than 3 seconds for a page to load and you can expect bounce rates of 50% and higher.

According to a survey performed by an additional one second on page load is a conversion decrease of around 7%. This means that if your website takes 10,000 in sales a week then one second is costing your business 36,000 a year. The same research also concludes that 64% of users who are unhappy with your website’s performance are also unlikely to visit your website again.


Graph Showing Consequences of Online Shoppers Dissatisfaction with Retail Site Performance


The Bigger Picture

With over 75% of the UK population now using smartphones, mobile browsing has surpassed desktop usage which makes speed more important than ever. Mobile networks are typically not as powerful, especially outside of cities, and with this comes a great demand for websites to be delivered efficiently. When on these slower networks (such as 2G) a single megabyte could add many valuable seconds to your page load time, in turn dramatically reducing conversions.

The time it takes for your website to load isn’t just important to your users; search engines are now using it as a ranking factor. If your website is slow, you can expect the likes of Google to be more favorable towards your competitors with faster sites.

Rendering Performance

A website does not only take time to be delivered over the network, it also has to be rendered by the user’s device (computed and drawn to the screen). This is very often overlooked when attempting to measure and improve a website’s performance but can have a huge effect on total load time. The time it takes for a website to ‘be drawn’ can vary massively across devices, more expensive and powerful devices will often render anything quickly – but what happens when you run the same website on an old and/or less powerful machine? You can expect that spinning wheel to keep going a while longer.

Rendering performance has become increasingly more important with the rise of smartphone usage, such a varying degree of computational power can produce sporadic rendering times across a range of smartphones. Rendering performance can be broken down to different processes, but ultimately boils down to the website’s structure and code – HTML, CSS & Javascript. It’s absolutely critical to modern development projects that rendering performance is considered at project inception.

The Basics

Here are some great basic tricks for optimising your website and decreasing that all-important page load time:

  • Minifying Assets: this involves reducing the file size of your images, stylesheets, HTML and Javascript usually through encoding and the removal of white-space.
  • Concatenating Assets: this basically means merging multiple assets of a similar type into one file. Doing this reduces the amount of requests your page makes.
  • Gzip Compression: modern browsers can decipher compressed files (Think of zipping a folder on your computer) which means much smaller files can be transferred over the network.
  • Browser Caching: setting up caching correctly through the use of cache and expires headers will prevent browsers from re-downloading files. When users navigate to other areas of your site they will experience an even quicker load time.
  • Server Caching: if your website has a Content Management System or does anything computational (such as loading a Twitter feed) then caching (remembering) the results of this process means that users will not have to wait for the computation to take place and are instead delivered the information they need instantly.
  • Content Delivery Network: using a CDN will make a considerable difference in website performance due to the global infrastructure they are built upon.

Performance Matters

The time it takes for you website to load and render is absolutely vital to project success, if it is not considered at the beginning of a project then your are effectively alienating a large portion of your potential customers. It’s simple really, a fast website means more sales!