<p>The concept of tourism experience has evolved to emphasize memorability, focusing not only on satisfaction but also on creating unforgettable experience. In the digital era, technologies have had a substantial impact on the retention of biological memory. However, limited research has focused on how sustainable tourism attributes foster memorable experiences and how technology aids tourist memory. Therefore, this research examines how sustainable tourism attributes can foster tourist loyalty through internal and external vivid memory. Sustainable tourism is measured through three dimensions: environmental, socio-cultural, and economic attributes. Internal vivid memory refers to the clarity and quality of biologically stored travel memories, while external vivid memory is associated with technologically enhanced memory recollections. A quantitative approach was adopted using a structured questionnaire administered to 432 international tourists across four Indonesian cities (Yogyakarta, Manado, Badung–Bali, and Surabaya). The data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The findings indicate that each sustainable attribute contributes significantly to the external vivid memory. However, environmental attributes do not significantly affect internal vivid memory. Furthermore, the results reveal that neither internal nor external vivid memory serves as a mediating variable between environmental attributes and tourist loyalty. In contrast, vivid memory partially mediates the effect of socio-cultural attributes on loyalty and fully mediates the effect of economic attributes. Moreover, the result shows that remembering through digital technology is more impactful on loyalty than biological memory. This study provides new perspectives on the role of technology and biological memory in enhancing tourist loyalty.</p>