Indonesia's digital education ecosystem has a wide range of control spaces, including geographical differences, gaps in infrastructure distribution, gaps in educators' digital capabilities, and gaps in different teaching methods. Thus, several scenarios or strategies must be used during the post-Covid 19 digital education transformation. In the learning process, learning strategies are needed based on the characteristics of students so that learning becomes effective and efficient. English is one of the languages used as a universal means of communication on an international scale. One of the most notable technological developments in recent years is the development of Duolingo smartphone app. This program incorporates the idea of "playing while learning" to make it more enjoyable and practical for deaf students to utilize when honing their vocabulary for vocabulary examinations. This research aims to determine the effect of Duolingo learning media on increasing the vocabulary of deaf students learning English in grade IX at SLB Sukabumi City. This research is quantitative. The research method used was a quasi-experiment with a pretest-posttest control group design. The population in this research was 36 deaf students in class IX at SLB Sukabumi City. Based on the results of the data analysis and the results of the hypotheses tested in this research, it can be seen that there was an increase in the vocabulary of deaf students in class IX at SLB Sukabumi City after using Duolingo learning media.