In this paper, we investigated the impact of an online classroom-based reading assessment on implementing practices in reading instruction among 30 EFL learners in an intermediate reading course at a public university in East Java, Indonesia. Our study aimed to develop an online classroom-based reading assessment and evaluate its efficacy in measuring students' reading skills. The online classroom-based assessment, characterized as systematic, comprehensive, instructional, diagnostic, and adaptive, yielded positive outcomes, as evidenced by specific trends in the qualitative analysis. While limitations were considered, the study's findings showcase the practical implications of incorporating online classroom-based assessment in monitoring student performance and evaluating teaching quality. The results emphasize the importance of online classroom-based reading assessment as a robust evaluation tool for aligning learning goals and needs. Overall, our study contributes valuable insights into the benefits of online classroom-based reading assessments and their potential to enhance traditional assessment methods in English as a Foreign Language (EFL) settings in this technologically advanced era.