Inspired by an Internet Retailer study, responsive design site builder UniteU Technologies tested page load speed on smartphones for 26 retailer volunteers at the 2014 IRCE. Load times are deathly slow; more speed can lead to many more sales, UniteU finds.

At June’s 2014 Internet Retailer Conference & Exhibition, exhibitor UniteU Technologies Inc. asked retailers to let the e-commerce and m-commerce technology provider test their sites to see how quickly their home and product pages loaded on smartphones. UniteU was inspired by the June cover story of Internet Retailer magazine, which showcased a study by Internet Retailer and mobile and web performance management firm Keynotethat concluded the home pages of retail responsive sites on average took more than 18 seconds to load on smartphones via a blend of 3G and 4G wireless connections. That kind of performance is the kiss of death.

Today, UniteU reveals exclusively to Internet Retailer that 20 of the 26 retail site home pages it tested took more than 13 seconds to load on smartphones, and that the average load time for the 26 sites was 25.75 seconds. With maximum load time recommendations (for blended wireless connection speeds) of 4.5 seconds from Keynote and 6.0 seconds from UniteU, 25.75 seconds is clearly far too slow.

Retailers in the UniteU test ranged from giants to very small e-retailers, the vendor says. UniteU is not revealing any of the volunteers from IRCE. UniteU tested on a blend of 3G, 4G LTE and cable modem Wi-Fi; the Wi-Fi, not used in the Keynote test, would help speed page loads. However, seven of the 26 retail sites tested by UniteU offered no mobile optimization whatsoever, which slows page loads. The rest were a mix of m-commerce sites optimized for smartphones (5), pure responsive design sites (7) and hybrid responsive design sites (7).

Pure responsive transmits from a server to a client web browser everything needed to build the site on all types of devices in one big package of data regardless of the device requesting a page. Hybrid responsive typically detects the type of device requesting a page and only sends from the server to the client web browser what is necessary to build a site for that device.

At an average of 29.83 seconds, product page load times on smartphones were worse than their home page counterparts, UniteU finds. The worst mobile product page load time was 50.41 seconds, UniteU says. It makes special note of this time because the site belongs to a multibillion-dollar retailer.


“In line with what Keynote and Internet Retailer found, the primary issue is the high correlation between page weight and the slow speed of 3G networks,” says Soumen Das, CEO of UniteU Technologies. “Secondarily, the number of server requests also has a significant impact on page speed.”

Pure responsive design sites deliver heavy payloads, as they cram everything needed to build a site on desktops, tablets and smartphones into one data package and dump that on a smartphone, which may be connected via 3G, Das says. And simple carelessness is another offender: Not optimizing page load size, especially when it comes to optimizing the size of images for conventional standalone m-dot m-commerce sites, damages performance, Das adds.

Das points to an Aberdeen Group study that shows a 1-second delay in web site page load time translates into a 7% loss in conversions. Based on that calculation, following are the smartphone page load times in seconds for a selection of the 26 tested retailers (3G times followed by 4G LTE times) and the conversion rate improvements if the retailers were to boost their load times to UniteU’s recommended 6.0 seconds, according to UniteU:

  • 11.32, 8.2, 37.1%.
  • 14.00, 10.45, 55.9%.
  • 17.69, 13.70, 81.7%.
  • 24.70, 5.20, 130.8%.
  • 39.00, 33.77, 230.86%.
  • 45.00, 15.48, 272.9%.
  • 49.62, 14.40, 305.2%.

Das recommends retailers make use of programming techniques UniteU uses to improve performance, including sprites (click here for more on sprites), JavaScript aggregation (click here for more on JavaScript aggregation) and minification (click here for more on minification). But Das contends the real trick to minimizing page load times on smartphones is to build hybrid responsive design sites, which is what UniteU now builds for its retailer clients. Hybrid responsive sometimes is also referred to as adaptive design. There are many flavors of hybrid responsive design, which, generally, first detects what type of device is making a page request and then only sends to the device what is needed to build a site for that device. This is very different, and much lighter, than pure responsive design.

UniteU’s flavor of hybrid responsive actually builds two versions of a site, one for desktops and tablets and another for smartphones, enabling the vendor to greatly reduce the amount of data sent to smartphones and thus speed up page load times.


“The big advantages come when we split the responsive payloads between desktop and tablet on the one hand and smartphones on the other,” Das says. “Each payload has fully responsive elements for the devices to which they are targeted. This approach delivers speed advantages as well as the design flexibility of responsive.”

Many merchants have a hard time managing simultaneous design changes for desktops, tablets and smartphones, Das adds.

“They seem to focus on one format at the expense of the others,” he says. “We think special attention needs to be paid to smartphones, especially with regard to non-optimized images or having too many images on the page. Our team frequently reminds merchants not to use a 500-kilobyte image where a 50-kilobyte image will do. One careless image has the potential to negate all the other hard-fought technical advantages.”

Follow Bill Siwicki, editor of the Internet Retailer Mobile 500 and managing editor, mobile commerce, of Internet Retailer, at @IRmcommerce.