What is a heatmap in UX research?
A heatmap uses a color spectrum from cool blues representing low activity to warm reds representing high activity to show the distribution of user behavior across an interface. Click heatmaps show where users click most frequently. Move heatmaps show where users move their cursor. Scroll heatmaps show how far down the page users scroll before leaving, revealing what content most users see and what only the most engaged users reach.
What can heatmaps reveal about UX design?
Click heatmaps reveal mismatches between designed affordances and user behavior: if users are clicking on non-interactive elements, those elements have visual properties that suggest interactivity. If users are not clicking on interactive elements, those elements may lack sufficient affordance. Scroll heatmaps reveal whether important content is positioned where users will see it or buried below the fold where few users scroll.
What are the limitations of heatmaps?
Heatmaps are aggregate visualizations that can obscure important patterns. A red zone on a click heatmap could represent many satisfied users or many frustrated users repeatedly clicking an unresponsive element. Heatmaps do not explain behavior: understanding why a pattern exists requires qualitative research like session recording or usability testing. They also aggregate behavior across all users, hiding important differences between user segments.