This study investigates the efficacy and complementarity of the Interactive Web Maps (IWM) and Nielsen heuristic sets in usability evaluations. Recognizing the limitations of traditional heuristics in addressing the specific needs of modern interactive systems, this research aims to validate the most recent version of the IWM heuristics through a comparative analysis with Nielsen’s widely established principles. The evaluation was conducted on the CulturaEduca platform, an innovative tool for visualizing geographic data, developed to integrate relevant information related to education and culture. Three main comparisons were performed: (1) assessing the differences between IWM and Nielsen in identifying usability issues, revealing distinct patterns in problem detection; (2) evaluating the evolution from IWM version 3 to 3.5, which demonstrated stable efficacy in detecting critical usability problems; and (3) analyzing the severity of issues identified by IWM, Nielsen, and the combined set, highlighting that while IWM excels in detecting severe issues, the combined set offers broader coverage of usability problems. The findings suggest that integrating the IWM and Nielsen heuristics provides a more diversified and detailed evaluation, confirming their complementary nature in capturing a wider range of usability issues.