Creating a compelling customer experience for online retail brands (i.e., e-retail brands) is vital for the success of online retailing. The extant research also emphasizes the need to study customer experience concepts for e-retail-brands. Customer experience with e-retail brands comprises a customer’s subjective, multi-dimensional psychological response to the e-retail brand-related stimuli. However, the availability of a valid and reliable scale to evaluate ‘customer experience with an e-retail brand’ (i.e., e-retail brand experience) is limited in the literature. Hence, this study aims to conceptualize, develop, and validate a scale to measure the E-retail brand experience using a mixed-method approach through three stages. In Stage ۱, potential scale items are generated and selected through semi-structured interviews, expert surveys, and literature review. In Stage ۲, scale items are reduced, and the scale’s dimensionality is assessed. In Stage ۳, items and their dimensionality are validated through different phases of factor analysis. The study developed a ۲۶-item nine-dimensional E-retail brand experience scale. The scale exhibits sound psychometric properties based on reliability and validity tests. This scale can assist online retail practitioners in measuring and contextualizing customer experiences with their E-retail brands. It also contributes to the literature to a great extent as it makes the online brand experience much more tangible and assessable for scholars in the field.