This study utilised a user-centred design (UCD) approach integrated into the Agile framework to develop Sarawak Cultural Heritage Progressive Web Apps (SCHPWA). The user experience (UX) of SCHPWA was evaluated using a combination of the User Experience Questionnaire (UEQ) and Importance-Performance Analysis (IPA) to measure six dimensions of UX. The evaluation involved 239 participants, comprising 184 females and 55 males. The results indicated that the SCHPWA scored above average in attractiveness, perspicuity, efficiency, and stimulation. However, the dimensions of novelty and dependability scored below average. Therefore, the attributes related to attractiveness, efficiency, stimulation, and perspicuity are grouped using IPA under Quadrant 2 (Possible Overkill), while novelty and dependability fall under Quadrant 3 (Low Priority). The study highlights the benefits of using a combination of UEQ and IPA for evaluating Progressive Web Applications (PWA). Furthermore, it suggests the potential to improve the UX of cultural heritage PWAs. These findings offer insights for designers and developers in optimising the UX of cultural heritage PWA.