<![CDATA[The rapid development of educational technology has increased students’ interest in technology-based learning; however, teachers still face limitations in providing innovative digital learning media. In addition, Algebraic Functions in advanced mathematics are considered abstract and challenging, resulting in relatively low student learning outcomes. This study aimed to develop a web-based learning multimedia using Google Sites for Algebraic Functions and to evaluate its validity, practicality, and effectiveness. The research employed a Research and Development (R&D) approach using the ADDIE model, consisting of Analysis, Design, Development, Implementation, and Evaluation stages. The subjects of this study were 28 students of class XI F1 at SMAN 2 Bukittinggi enrolled in the Advanced Mathematics course. Data were collected through validation sheets, response questionnaires, and learning outcome tests, and analyzed using descriptive quantitative techniques. The results showed that the developed multimedia achieved a validity score of 84.52%, indicating that it was valid for instructional use. Practicality testing revealed very practical criteria, with scores of 88.81% from students and 96% from teachers. Furthermore, the effectiveness test demonstrated a learning mastery level of 83.39%, categorized as very effective. These findings indicate that the Google Sites-based learning multimedia is valid, practical, and effective for supporting the teaching and learning of Algebraic Functions. The study contributes to the integration of web-based technology in mathematics education and provides an alternative digital learning resource for improving student engagement and achievement.]]>
