Khusaini Ketua Penguji Isnaniah Penguji 1 Tenia Ramalia Penguji 1 Khilda Sopia Dosen Pembimbing 2 Putri Aliya Rahma Pengarang

This study aims to investigate the effect of Quizizz on students' mastery of English vocabulary. Quizizz is an application that aims to develop student vocabulary learning at Madrasah Aliyah Attaqwa. Most of the students in senior high school have less ability in learning vocabulary, especially in memorizing new words. Therefore, teachers need to find the right media to improve vocabulary mastery. Several applications can be used via smartphone for vocabulary learning purposes. The purpose of this study was to determine the effectiveness of using the Quizizz application as an influence on students' mastery in learning vocabulary. This type of research is Quasi Experimental with quantitative methods. Researchers used multiple choice tests. The participants were 47 students who were divided into an experimental group and a control group. The results show that the use of the Quizizz application has an effect on students' mastery in learning vocabulary. Students feel enthusiastic, and not bored because the teacher creates an interesting and fun lesson for activities in the classroom when studying English vocabulary using Quizizz.