PurposeThe novel coronavirus (COVID-19) remains a global public health emergency as declared by the World Health Organization (WHO). The COVID-19 impacted educational institutions around the world, and they were shut down to minimize the fatalities and spread of the infection. Educational institutions around the world, including Bangladesh, started to conduct online classes as an alternative to physical classes. Therefore, this study assesses the effectiveness of online classes in terms of information and communications technology (ICT) readiness, online class assessment, online class participation, and convenience and flexibility for the educational institutions of Bangladesh.Design/methodology/approachTo fulfill the objective of the study, data were collected from 817 teachers and students. Additionally, the partial least squares (PLS) regression method was adopted as a quantitative technique.FindingsThe study shows that online class participation, online class assessment, and convenience and flexibility have positive relationships with ICT readiness and the effectiveness of online classes. At the same time, the challenges of online classes have negative relationships with ICT readiness and the effectiveness of online classes.Practical implicationsThe study suggests that the government should ensure stable internet connectivity access across the country so that both students and teachers can participate in online classes effectively. Moreover, educational institutional authorities should extend support to the institutions for developing proper ICT infrastructure.Originality/valueICT infrastructure readiness is the backbone for effective online education; however, before the COVID-19 pandemic, online education was almost non-existent at the educational institutional level in Bangladesh. The country started developing the ICT infrastructure only when online classes were scheduled to start, and the development is still ongoing. Hence, this study used ICT readiness as a mediator factor. Moreover, primary data are used in this study. The findings of the study will help academicians and policymakers to better understand the effectiveness of online classes.