Some retailers launched online deals well in advance of Thanksgiving, Black Friday and Cyber Monday.
The two retailers topped web site availability testing for Internet Explorer and Firefox, respectively.
JCPenney.com and OfficeDepot.com placed first among large retailers in August availability tests, says Compuware Gomez. Last month, online shoppers using Internet Explorer could access JCP.com 99.96% of the time. OfficeDepot.com posted 99.94% rating in Firefox testing.
LLBean.com came in second in Internet Explorer tests with a score of 99.94% availability. Williams-Sonoma.com posted the third best score at 99.88% while Amazon.com and OfficeMax.com tied for fourth place (99.84%).
Apple.com and Walmart.com tied for second place in Firefox testing at 99.93%. Newegg.com came in fourth (99.92%) followed by Dell.com (99.90%) in fifth place.
The average Internet Explorer availability for the 19 retailers measured in August was 99.66%, according to the Compuware Gomez Benchmarks study. The average Firefox availability for the same group of retailers last month was 99.69%.
Availability represents the percentage of tests that correctly load.