The emergent of the contiguous disease COVID-19 (Corona Virus Disease–2019), emerged in Wuhan, China forced the countries to announce lockdown in order to control the spread of the disease. The nationwide or localised closure of the educational organisations influences the lives of millions of learners. As a response, the institutions stimulated digital learning to facilitate continuity of education for the learners. Though the virtual classroom is the only alternate, both the teachers and students face numerous problems related to network, learning atmosphere and mainly in health conditions. This paper analyses research papers and identified the factors affecting efficacy of online education. The factors are classified under ten categories. Identifying factors having high impact in the outcome of online education can be analysed for enhancement.