Impulse buying represents an unplanned and spontaneous purchasing behavior wherein consumers, upon exposure to specific environmental stimuli, engage in immediate purchase actions. Given the significance of this phenomenon, the primary objective of the present study is to elucidate a conceptual model of impulse buying within the online shopping domain of internet-based retail platforms, with Digikala online store serving as the empirical case. Methodologically, this research is classified as applied and developmental in terms of purpose, field-based regarding data collection, and qualitative in terms of procedural execution. To develop the proposed model, thirteen marketing and sales managers and experts affiliated with Digikala were selected through snowball sampling until theoretical saturation was achieved. In-depth, semi-structured interviews were subsequently conducted with the participants. The interview data were analyzed using thematic analysis via MAXQDA software, undergoing a systematic coding process encompassing open, axial, and selective coding stages. Following reliability assessment (through test-retest procedure and Kappa coefficient calculation) and validity evaluation (via member checking and interview triangulation), the analysis yielded 79 basic themes, 15 organizing themes (components), and 5 global themes (dimensions). These overarching dimensions were identified as: product appeal, momentary emotions, convenience and purchase speed, pricing and promotional discounts, and social influences. Based on these findings, the final conceptual model was proposed. The results indicate that the identified themes exert a significant influence on customers' impulse buying behavior within the online shopping context of internet-based retail platforms.