Visitors expect your website to load quickly, and will leave if you make them wait too long. People will leave in a matter of seconds, and fractions of a second are significant here. Designing an attractive and usable website is important, but its performance shapes how it is used in practice. If visitors don’t even load your page, there’s no chance of them converting, and this reduction in conversions hurts your profitability. Taking a positive view of this behaviour, there’s an opportunity to increase conversions simply by improving your page speed.
Evidence for the impact of page load speed on business performance
Walmart: reducing page load time by 1 second causes an up to 2% increase in conversions. (Study slides, analysis)
Yahoo: reducing page load time by 0.4 seconds increased traffic by 9%. (Reference)
Google: increasing page load time from 0.4 seconds to 0.9 seconds decreased traffic and ad revenues by 20%. (Reference)
Amazon: every 0.1 second increase in load time decreases sales by 1%. (Reference)
A 1 second delay in page response can result in a 7% reduction in conversions. (Reference)
Radware: “one-second HTML delay resulted in… 3.5% decrease in conversion rate…” (Reference 1, reference 2)
Shopzilla: reducing average load time from 6 to 1.2 seconds increased revenue by up to 12%. (Reference)
Mozilla: reducing average load time by 2.2 seconds increased conversions by 15.4%. (Reference)
AutoAnything.com: 50% reduction in page load times increased sales by 13%. (Reference)
Obama campaign: reducing load time by 60% increased donation conversions by 14%.
How to test and improve page speed
To see how fast your pages load, go to gtmetrix.com or webpagetest.org and plug in your URL (or a competitor’s ;)). GTMetrix uses insights from Yahoo and Google’s separate page speed testing tools, and draws from their banks of improvement recommendations.
These free services will provide recommendations for how a developer could improve your site’s performance. Things like compressing images, making effective use of browser caching of static assets, and optimising the critical rendering path.
To learn more about the practical measures you can take to improve page load speed, this free online course on page load speed is useful.