This study aims to describe: (1) Implementation of online learning using the WhatsApp application for Indonesian subjects (2) Constraints that occur in online learning using the WhatsApp application for Indonesian subjects.This research was conducted at SMP Negeri 1 Rowokele in January - May 2021. This typeof research is descriptive qualitative with a type of phenomenological research that describes the implementation of online learning using the WhatsApp application. The data from this study were obtained through interviews with junior high school teachers, observation in the form of passive participation observation and documentation as supporting data from the interview results.
The results of the study show that teachers have used WhatsApp in online learning by utilizing various available features such as photo, video, document and video call features. Then the use of WhatsApp in learning has several obstacles, namely signal interference, full cellphone memory quota, lack of parental attention, teacher ability, student enthusiasm, and environmental influences. From the results of this study it is suggested that educators be able to make innovations in learning, especially by using the features thatexist inWhatsApp, mastering and using ICT in the learning process in the network(online).