Objective: The teaching-learning of English as a foreign language process is not a simple task to develop. Teachers look for different ways to attract and engage students in their classes. One of those ways include using various mobile phones applications to take advantage of students' everyday uses of these devices. Instagram is one of the most popular mobile applications and the focus of this research. Therefore, this investigation aimed to measure the effectiveness of using Instagram as a tool for learning English. Methods: A mixed-methods design was chosen for this paper. A survey, pretest-posttest, and semi-structured interviews were the chosen data collection tools. Descriptive analysis was used on the survey, the pretests and post-tests were analyzed using a paired T-test, and the interviews followed a general inductive approach. Results: The descriptive analysis of students' responses to the survey shows that learners have a positive attitude toward using Instagram to learn English (M=3.38, SD=1.084). Results of the Paired T-test showed there is a significant difference between Before (M=70.4, SD=13.1) and After (M=74, SD=12.1), t(126)=2.4, P=0.017. Also, informants mentioned that using Instagram to post tutorials was good for them. Conclusion: The intervention was successfully adopted as the analysis revealed a significant difference between the pretest and post-test. Also, participants explained that they have found using Instagram positive for their English language development.