As digital platforms become the primary touchpoint for many service providers, the management of users’ cognitive resources becomes critical for improving perceived digital service quality. This study examines the relationship between extraneous cognitive load and perceived digital service quality using a mixed-method approach and a within-subjects experimental design. Ten participants completed two versions of an online air travel booking flow and rated their experience, one imposing higher extraneous cognitive load than the other, which was achieved by violating users’ established mental models through the experimental manipulation of information architecture. Quantitative data was collected through subjective self-reported mental effort and perceived quality ratings on a seven-point Likert scale, and analyzed using non-parametric Wilcoxon signed-rank tests and a Spearman’s correlation analysis. Qualitative data was collected by taking notes of participants’ feedback during the experiment, and analyzed through affinity diagramming. Findings indicate an inverse relationship between extraneous cognitive load and perceived digital service quality, concluding that minimizing extraneous cognitive load is an important differentiator for service providers to remain competitive and ensure higher perceived digital service quality.