The Sri Lanka Library Association (SLLA) has transitioned from conventional teaching-learning to online education. However, no further research has been conducted to assess the successfulness of this online learning from the students’ perspective. Addressing this issue, the objectives of the study were to measure the satisfaction, successfulness and challenges faced by diploma students with online learning at SLLA during the pandemic. The survey was conducted using Google Forms and WhatsApp, with approximately 225 students approached and 194 (88.5%) responding. Data analysis was performed using SPSS software, and statistical tests were applied using the Wilcoxon signed-rank test and Rosenthal r value. Results regarding students’ successfulness indicated that more than 70% agreed with online education during the lockdown. Additionally, students expressed that the online mode was more secure for their health 152(73%) and for transportation 129(66.49%) compared to face-to-face classes and distance mode classes. Concerning satisfaction, 97(50%) students were either highly satisfied or satisfied with online teaching, Regarding the devices used, majority of students (78.9%) used smartphones; whereas the use of laptops, desktops, and tablets was less commonly used (17.5%).Challenges identified were recorded as, clearly hearing the lectures 88(45.4%), expensive equipment requirements 85(43.8%), poor internet connection and difficulty in logging on in a timely manner 84(43.3%) each, and a feeling of isolation while attending class 82(42.3%). Overall, the majority of students were satisfied with online learning and they are moving towards the health security, transportation convenience, and ability to attend classes from home, despite the challenges faced. It is recommended to enhance student interaction and improve the practical effectiveness of the online course. Additionally, action should be taken to address the challenges faced by the students, redesign the online course to improve practical effectiveness, and implement best practices in online education.