Source: Radware [download page]
Notes: The median load time for home pages of the top 100 US retail websites (as ranked by Alexa) has slowed yet again on a year-over-year basis, increasing from 7.2 seconds in Summer 2013 to 10.7 seconds in Summer 2014. Concurrently, the median time to interact (TTI) – which measures the point at which a page displays its primary interactive content – has also slowed from 4.9 seconds to 6.2 seconds. Radware blames increasing page sizes along with a failure to adequately optimize images. Three usability errors also continue to plague sites, per the study:
- “Pages that are blank in the browser for several seconds, then suddenly populate;”
- “Pages in which the call to action is the last thing to render;” and
- Pages in which a popup blocks the main page before it finishes rendering.”
About the Data: Radware describes its methodology as follows:
“The tests in this study were conducted using an online tool called WebPagetest ”“ an open-source project primarily developed and supported by Google ”“ which simulates page load times from a real user’s perspective using real browsers.
Radware tested the home page of every site in the Alexa Retail 500 nine consecutive times. The system automatically clears the cache between tests. The median test result for each home page was recorded and used in our calculations.
The tests were conducted on June 11, 2014, via the WebPagetest.org server in Dulles, VA, using Chrome 35 on a DSL connection.
In very few cases, WebPage test rendered a blank page or an error in which none of the page rendered. These instances were represented as null in the test appendix.
Also, in very few cases, WebPagetest.org rendered a page in more than 60 seconds (the default timeout for webpagetest.org). In these cases, 60 seconds was used for the result instead of null.
To identify the Time to Interact (TTI) for each page, we generated a timed filmstrip view of the median page load for each site in the Alexa Retail 100. Time to Interact is defined as the moment that the featured page content and primary call-to-action button or menu is rendered in the frame.”