UX Glossary · H
Heat map
Also: Heatmap
A visualisation of where attention, clicks or scrolling concentrate on a page.
A heat map overlays aggregated behaviour on a page as colour, warm where activity concentrates and cool where it does not. Three kinds are common: click maps, scroll maps showing how far down people get, and eye-tracking maps showing gaze.
What each is worth
Scroll maps are the most reliably useful. They show where the audience actually stops, which settles arguments about page length with data instead of opinion.
Click maps are useful with a caveat: they show clicks on non-interactive elements too, which is a genuinely valuable finding. Repeated clicking on something that is not a link means people expect it to be one.
Gaze maps need dedicated equipment and careful interpretation.
How they mislead
A heat map aggregates very different people into one picture. Visitors arriving from search with a specific question and visitors browsing produce opposite patterns, and averaged together they produce a warm blur that describes nobody. Segmenting before drawing conclusions is essential.
They are also seductive. A colourful image feels like evidence, and stakeholders treat it as more conclusive than the underlying sample supports.
In practice
Treat a heat map as a question generator. It shows where to look, and a handful of usability tests on that spot explain what is happening.