Top Retail Website Load Speeds Continue to Slow Down
by MarketingCharts staff
The median load time for home pages of the top 500 US retail websites (as ranked by Alexa) continues to slow down, climbing to 7.72 seconds during the Summer from 7.65 seconds in the Spring of this year, and far above the ideal load time of less than 3 seconds, per results [download page] from Radware’s latest E-Commerce Page Speed and Web Performance study. The report also introduces a new metric – “Time to Interact” (TTI) – which analyzes the “point at which a page displays its primary interactive content.”
That content could include feature banners with functional call-to-action buttons, for example. TTI is a key gauge of how quickly a page can deliver a satisfactory user experience, according to the researchers, as well as how rapidly the page can accomplish the site owner’s goals.
Radware believes an ideal TTI should be 2 seconds or less. The median TTI among the top 100 e-commerce site was more than double that amount, at 4.9 seconds. In fact, more top sites had a TTI of at least 8 seconds (9%) than of less than 2 seconds (8%). In order to speed up TTI, the researchers recommend that site owners:
“Defer rendering ‘below the fold’ content;”
“Ensure that interactive features, such as carousels, are optimized to load early and quickly;”
“Defer loading and executing non-essential scripts;” and
“Use AJAX for progressive enhancement.”
The median page was 1,095 kb in size and contained 91 resources, down from 93 in the Spring, but up from 89 in Fall 2012.
Some top retail websites continue to not employ best practices, although on the whole there has been a general improvement. 90% enable keep-alives (up from 86.4% in the Spring) and 58.4% use a content delivery network (CDN), up slightly from 57.6%.
Testing the load times of the Alexa Retail 500 across several popular browsers revealed that Firefox had the fastest load time (7.42 seconds), slightly ahead of Internet Explorer 10 (7.67 seconds) and Chrome (7.72 seconds).
About the Data: Tests in the Radware study were conducted using a tool called WebPagetest.org, an open-source project primarily developed and supported by Google. Researchers tested the home page of every site in the Alexa Retail 500 nine times in a row. The median test result for each home page was recorded. Tests were conducted over a 2-week period, from June 24-July 5 2013, via the WebPagestest.org server in Dulles, VA using Internet Explorer 10, Firefox 21, and Chrome 27 on a DSL connection. In very few cases, WebPagetest.org rendered a blank page or error in which none of the page rendered. These instances are represented as null. Also, in very few cases, a page was rendered in more than 60 seconds – in those cases, 60 seconds was used for the result instead of null.
To identify the time to interact (TTI) for each page, Radware generated a filmstrip view of the page load for the median page for each site in the Alexa Retail 100. TTI was defined as the moment that the featured page content and primary call-to-action button or menu was rendered in the frame.