Hotjar

Hotjar is a behaviour analytics tool that combines heatmaps, session recordings and on-page surveys to show where visitors click, scroll and give up.

A heatmap aggregates clicks or scroll depth from many visits onto a single static snapshot of the page, and that mechanism is also its main limit, since dynamic pages and the mobile and desktop layouts differ and the map shows only one version. Recordings and surveys add the qualitative layer that explains why, but on small samples. The common error is drawing quantitative conclusions from these views: a hot spot on a non-clickable element is a lead, not a measurement, and it should be confirmed against that page's metrics in an analytics tool.