In the current era of globalization, the pursuit of learning foreign languages has gained significant popularity. In Vietnam, beyond English, languages such as Chinese, Korean, Japanese, etc., are on the rise. At the University of Languages and International Studies - Vietnam National University, Hanoi, postgraduates are required to acquire proficiency in a second foreign language alongside their major, and many have chosen Chinese. To achieve the B2 level in Chinese, some postgraduates opt for advanced courses at language centers, while others hire private tutors. Regardless of the method, many postgraduates integrate the Duolingo language learning platform into their schedules during free time. Duolingo, offering courses ranging from basic to advanced levels, not only provides convenience but also enhances the enjoyment of the learning process. Despite the widespread adoption of Duolingo as a language learning app, there is currently a lack of comprehensive research on the advantages and limitations of Duolingo for learning Chinese as a second foreign language, particularly for postgraduates. Hence, this study aims to evaluate the perspectives of postgraduate students when utilizing Duolingo to learn Chinese as their second foreign language.