PetSmart shaves nearly 3 seconds off mobile page load time

Some big images were holding the m-commerce site back, Keynote Systems observes.

Bill Siwicki

“The more, the merrier” is not a mobile performance axiom. Quite the contrary, as the fewer elements a retailer includes on a mobile commerce web site page, the greater the likelihood the page will load quickly and successfully.

PetSmart’s m-commerce site is a case in point. Last week, the pet supplies chain retailer removed three of four large images from its m-commerce site home page, reports mobile and web performance management firm Keynote Systems Inc. The result was significant. It shaved 2.85 seconds off its page load time, going from 8.14 seconds for the week ending Sept. 23 to 5.29 seconds for the week ending Sept. 30, a 35% reduction, on the Keynote Mobile Commerce Performance Index.

The removal of the images also boosted the success rate of the site—the percent of the time a page loads completely and successfully. It jumped from 99.06% for the week ending Sept. 23 to 99.56% for the week ending Sept. 30. The weighted and combined load time and success rate gives PetSmart an index score of 918 out of 1,000, placing it at berth No. 8, up from No. 19 the previous week.

“We observed in August that PetSmart experienced significant load time improvement, but there were still four large image objects hosted by external content delivery networks slowing down the overall page load time,” says Herman Ng, mobile performance evangelist at Keynote Systems. “Upon close examination of last week’s data, we noticed that PetSmart had removed three of the four image objects hosted by the content delivery networks from its mobile page. As a result, the overall page size reduced more than three-fold from approximately 230 kilobytes to 63 kilobytes. By doing so, the site improved its page load time significantly. In addition, PetSmart’s page load time became much more stable, giving end users a more consistent experience.”

PetSmart did not respond to a request for comment.

Barnes & Noble topped the index for the week ending Sept. 30 with a load time of 5.06 seconds and a success rate of 99.89% for a score of 976. Buy.com came in second with a load time of 3.70 seconds and a success rate of 99.78% for a score of 971. And HSN Inc. came in third with a load time of 4.50 seconds and a success rate of 99.78% for a score of 963.

The average load time for all 30 retailers on the index last week was 7.66 seconds, the average success rate 99.20% and the average score 834.

Click here and then click on Keynote Mobile Commerce Performance Index Part 1 and Part 2 to see this week’s complete results for all 30 retailers on the index.

Keynote Systems measures 30 representative m-commerce sites exclusively for Internet Retailer. The sites include merchants in multiple categories and channels, and of multiple sizes, ranging from such giants as Amazon.com Inc. to midsized retailers like Toolfetch.com LLC. Keynote tests the sites in the index every hour Monday through Sunday from 8 a.m. through midnight Eastern time, emulating three different smartphones on three different wireless networks: Apple Inc.’s iPhone 4 on AT&T, the HTC Evo on Sprint and the Droid X on Verizon. The HTC Evo and the Droid X run Google Inc.’s Android operating system. Keynote runs the tests in New York and San Francisco.

Keynote combines a site’s load time and success rate, equally weighted, into a single score. Given that both performance and availability are important, the score reflects the overall quality of the home page; a higher score indicates better performance. Scores also reflect how close sites are to each other in overall quality. The index average score is the midpoint among all the sites’ scores.


Keynote Systems, Keynote Systems Inc., m-commerce, m-commerce site, m-commerce site performance, Mobile, mobile commerce, mobile shopping, PetSmart, smartphones