Online learning is a revolutionary trend of educational technology today; particularly, online learning has become the main alternative to traditional learning during the Covid-19 pandemic and in the new normal period. Various studies have shown that online learning has varying effectiveness at all levels and types of education; however, it is worth noting that still a number of learners do not accept the mode of online learning and learner retention has been suggested as one of greatest weaknesses in online education. The current study used the descriptive method to examine online learners’ perceptions towards online learning as well as to understand reasons for their retention in online courses. The results revealed that most of the learners, especially young learners still preferred traditional face-to-face learning to online learning because of some problems they expected while doing online learning, such as lack of facilities and lack of necessary interactions. However, the retention rates are relatively positive, indicating the perceived quality of online programs at a center of foreign languages in Vietnam.