In brief: A heatmap displays the intensity of values through colour. On a website it can visualise clicks, pointer movement or scroll depth, and each type has different limitations.
How I use a heatmap in practice
I test a heatmap on real content and devices, not only in a design. I look at the first impression, readability, information order, error states and the ability to reverse a step. Observing several people often reveals a more specific problem than a long team discussion.
What to watch for
An attractive output is not automatically usable. A heatmap can meet an aesthetic intention while hiding important information, slowing a page or making controls harder to use. Be careful about testing only on a large monitor with ideal content.
Questions for decisions
- Which task does a person want to complete on the page?
- Where can they hesitate, make an error or lose context?
- Does the solution work on mobile, with a keyboard and on a slow network?
- Which signal will show that the change genuinely helped?