Impromptu speaking has been utilized as an assessment project in teaching and learning English for sophomores at University of Languages and International Studies, Vietnam National University. This can be considered a unique one due to the application of Flipgrid platform in the era of online teaching during Covid-19 pandemic. Flipgrid is a website which helps students videotape their speaking performance. With such reason, it acts as a potential platform for teachers to assess impromptu speaking online as well as give live comments and send reactions to different videos. In general, all 30 chosen participants feel excited about this motivating method rather than the offline version for several factors. Specifically, better learner autonomy is recognized as the most obvious plus point, a driving factor leading to their future success in studying English. In addition, the impact on speaking skill cannot be overlooked; nonetheless, some certain shortcomings are inevitable because of online platform.