This paper discusses the usage of WhatsApp grouping class for increasing students' English ability. This study uses descriptive qualitative research methods, with primary data in the form of semi structured online interviews, participatory observation, documentation and test result. Purposive sampling technique used to choose Informants with total 177 active members of the WhatsApp group from 8 classes. The results pretest and posttest show student's achievement increase. This achievement as evidence that WhatsApp group can be as tool or media for supporting English learning outside class. The interview also showed the majority of informants stated that existence of WhatsApp Group is useful to increase students' English ability including listening, writing, reading and speaking competencies with a series of drilling activities and interactions in groups, students are proven to be more active in English, improve their ability to read, listen, write and improve vocabulary.