Technology advancement has led to increased development of students’ language and social skills. Different strategies in acquiring or learning a new language would help students understand and use the language better. However, a lack of vocabulary skills may cause students to lose interest in the language. Thus, this study investigates Teaching English as a Second Language (TESL) undergraduates’ perceptions towards using YouTube videos to improve and promote vocabulary learning. The research objective was to determine how undergraduate TESL students felt about using YouTube for studying and how their perceptions of vocabulary skills had improved. The investigation employed a quantitative research approach, and descriptive statistics were utilised to examine the data. The research had 131 students altogether. The research instrument was a questionnaire distributed to the participants via Google Forms. Most respondents agreed that YouTube is an excellent educational tool for improving vocabulary development built on the outcomes. Other than that, the research findings propose that YouTube may be employed as an educational tool to learn a new language and improve one's vocabulary skills. According to current trends, future research could be conducted to study the effectiveness of other digital platforms in improving vocabulary skills. It will provide a broader perspective on students learning efficiently via digital educational tools. In addition, research can also be conducted to identify the perceptions of students and instructors from various levels and backgrounds on current technological tools that can help improve vocabulary skills.