This study aims to examine the positive effect of website quality and consumer characteristics on impulsive buying behaviour. The consumer characteristics examined in this study are excitement and product knowledge, which are mediated by buying intention in their relationships toward impulsive buying behaviour. In recent years, the tendency to make online purchases through e-commerce has increased sharply, especially during the pandemic that requires people to stay at home. Tokopedia, one of the largest e-commerce platforms, has the highest gross merchandise value in Indonesia. Even so, the number ofTokopedia website visitors has been shown to be in second place compared to Shopee.Therefore,a researchabouttheeffect ofwebsite qualityand consumer characteristics on Tokopedia's consumers' impulsive buying behaviour is needed.The sampling technique used in this study is the non-probability purposive sampling. The sample was 191 respondents with a data collection method in the form of electronic questionnaires. Data was processed using the Partial Least Square-Structural Equation Modelling method with SmartPLS software. The results showed that website quality do not significantly influence impulsive buying behaviour, while excitement and product knowledge have a positive and significant effect. In addition, buying intention has no mediating effect on the relationship between the two consumer characteristics and impulsive buying behaviour. The managerial implication of this study would provide several recommendations for Tokopedia on enhancing consumer’s excitement and product knowledge in the effort of increasing impulsive buying behaviour.