<![CDATA[Mount Merapi eruptions frequently pose high risks, such as volcanic ashfall, lahar floods, and pyroclastic flows. Consequently, mitigating these risks requires building the preparedness capacity of communities vulnerable to the disaster. Effective preparedness relies on information that is accurate, accessible, relevant, and actionable, enabling communities to prepare for and respond to eruption risks. Advances in digital technology offer opportunities for cyber extension specifically through disaster focused WhatsApp Groups (WAGs) to disseminate information and conduct disaster education. This study aims to analyze the effect of cyber extension via WhatsApp Groups on community preparedness capacity regarding Mount Merapi eruption risks in Dukun District, Magelang Regency, Central Java. A quantitative approach with an explanatory design was employed, surveying 200 respondents. Cyber extension (Variable X) was measured based on information system success using the DeLone and McLean Information Systems Success Model, while community preparedness capacity (Variable Y) was measured across pre-disaster, during-disaster, and post-disaster stages. Data analysis was conducted using Structural Equation Modeling Partial Least Squares (SEM-PLS). The results indicate that successful cyber extension via WhatsApp Groups. Perceived benefits serve as a significant instrument for strengthening community preparedness capacity against Mount Merapi eruption risks (path coefficient β = 0.192, T-statistic = 2.490, p-value = 0.013). An R² value of 0.383 indicates that cyber extension explains 38.3% of the variation in community preparedness capacity, while the remaining 61.7% is influenced by factors outside the research model.]]>
