Why page load speed is important – the impact of site speed on conversions and revenue

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.

  • martinlugton

    Here’s a resource with summaries of performance case studies


  • martinlugton

    Related article by Gerry McGovern http://gerrymcgovern.com/new-thinking/customer-experience-all-about-speed


    The overwhelming expectation of digital is that it will be fast. Impatience is the defining characteristic of online behavior.

    “We wanted to understand how much the speed of our website affected user engagement,” Matt Chadburn and Gadi Lahav wrote for the Financial Times in April 2016. “Using that data we then wanted to quantify the impact on our revenue.”

    They found that a 1 second delay in page downloads caused a 4.9% drop in the number of articles read. A 3 second delay caused a 7.2% drop. While loyal customers were prepared to be somewhat more patient, people who used the site less frequently “showed an extreme reaction to even a short delay.”

    The Financial Times found that the slower the website, the lower the subscription renewal rate. There was also a negative impact on advertising revenues. “When it comes to the speed,” the authors noted, “even one second can mean hundreds of thousands—if not millions—of revenue either gained or lost.”

    Ronan Cremin, writing for mobiForge in April 2016, referenced an Alexa study which found that the top ten sites on the Web are significantly lighter than other sites. The study showed that while page size for the top sites rose until 2014, after that the size began to drop substantially, as the page size for other sites continued to quickly grow.

    When GQ magazine reduced its page load time from 7 seconds to 1.5, unique visitors rose from 6 million to 11 million in one month. A 2015 study by Radware stated that “a site that loads in 3 seconds experiences 22% fewer page views, a 50% higher bounce rate, and a 22% fewer conversions than a site that loads in 1 second, while a site that loads in 5 seconds experiences 35% fewer page views, a 105% higher bounce rate, and 38% fewer conversions.”

    Google discovered that even a 400 millisecond delay had a significant impact on revenue. (That’s less than half a second.) “We had a similar experience at Amazon.com,” Greg Linden states. “In A/B tests, we tried delaying the page in increments of 100 milliseconds and found that even very small delays would result in substantial and costly drops in revenue.”

    When an engineer came to Jeff Bezos (founder of Amazon and owner of Washington Post) and told him that he could reduce page load times for the Washington Post website to 2 seconds, Bezos’ response was that this was not enough, that they needed to be thinking in milliseconds. When a programmer brought an early version of Gmail to show to Larry Page (founder of Google), Page’s response was that it was taking 600 milliseconds to load and that that was too slow.

    The minds that are truly focused on customer experience are thinking in milliseconds. Speed, simplicity and usefulness are the defining characteristics of great Web brands.

  • martinlugton

    53% of mobile site visits are abandoned if pages take longer than 3 seconds to load.