Abstract :
M-commerce is the activity of buying and selling products or services using mobile devices. Tokopedia is one of the e-commerce that currently ranks 3rd version of Playstore on android-based devices and 2nd in Appstore version on IOS-based devices. Tokopedia has other features such as credit purchases, bill payments, transportation ticket reservations, credit installments, investments and insurance and others. The high ranking and the number of features are certainly offset by the good usability that users feel on the app. To know the usability of an application needs to be done Usability Testing on the application. Usability testing was conducted to 20 participants with proportional random sampling on the student population with android and IOS operating systems. This study obtained the value of Tokopedia application usability of 4.14 which means the usability of Tokopedia application can be said to be good and comfortable to use by users. The experience between android and IOS users also produced good value as evidenced by the independent sample t-test result of 0.292 while the experience of male and female users also gained good experience with independent sample ttest results of 0.756. The percentage of aspects in the USE questionnaire was obtained by 84% for the systemaspect, 83% for the user aspect and 82% for the interactionaspect. The study also obtained an average time of 225.6 seconds, an average error of 2.7, an average success rate of 4.6, an average time efficiency of 0.04 tasks/s and an average overall relative efficiency of 89%. Keywords: UI/UX, Usability Testing, USE Questionnaire