The results of online learning were not optimal, as evidenced by the unsatisfactory learning outcomes. These issues influenced students who had a poor understanding of concepts and those who were quick to learn. It was the reason for the study that aims to analyze the effectiveness of study, explore, implement, evaluate (SEIE) model e-learning based on project-based learning (PjBL) on the conceptual understanding and agility of students. The research design is a posttest control group design, which is a quasi-experimental design. The sample size for this study is 58 students, including 28 in the experimental group and 30 in the control group. The study used test and questionnaire methods to collect research data. A questionnaire instrument that included 30 statements was used to evaluate their learning agility, and a test instrument in the form of 10 essay questions was utilized to evaluate their conceptual understanding. As data analysis techniques, quantitative descriptive analysis and inferential statistical analysis utilizing MANOVA were applied. The findings revealed that the SEIE model e-learning based on PjBL was beneficial in improving students' ability to understand concepts and their agility as learners, both partially and simultaneously. This condition was indicated by the value of sig. < 0.05. As a result, the SEIE model e-learning based on PjBL was effective on students' ability to understand concepts and their agility, both partially and simultaneously. Thus, this model became a learning recommendation for improving conceptual understanding and agility.