How a heatmap works
A small script records where visitors interact with a page and aggregates many visits into a single picture, with warm colours marking the busy areas and cool colours the quiet ones. There are several distinct types, and confusing them is the first mistake: a click map shows where people tapped or clicked, a move map shows where the cursor travelled, a scroll map shows how far down the page people reached before stopping, and an attention map weights areas by how long they stayed visible on screen.
All of them are summaries. A heatmap tells you what happened in aggregate; it cannot tell you why, and it flattens together visitors with completely different intentions unless you filter it first.
Why heatmaps matter
They answer questions analytics cannot. A report can say a page converts poorly. A scroll map can show that almost nobody reached the section carrying the offer, and a click map can show people tapping a heading that is not a link because it looks like one.
They are also the quickest way to settle an internal argument about layout, and they work on sites too small to test. A click map and a handful of recordings on one important page often produce a clearer list of things to fix than a month spent watching a dashboard.
Common mistakes with heatmaps
Reading a blended map is the big one. Mobile and desktop layouts are different pages in practice, and combining them produces a picture that describes neither. The same applies to mixing traffic sources, since branded visitors and cold ad clicks behave differently on identical pages.
The second mistake is concluding from too few sessions, where one enthusiastic visitor creates a warm spot that means nothing. The third is treating heat as approval: a bright cluster can mean interest, or it can mean confusion, because people click repeatedly on things that are not working. A map gathered across a redesign, or on a page whose layout changes with the visitor, is quietly comparing different pages under one image.
How to act on it
Choose pages where a decision is being made — the main service page, the pricing page, the checkout — rather than pointing the tool at the whole site. Segment by device before you look at anything, and let the map gather long enough that the pattern stops shifting.
Use it to generate questions, then answer them elsewhere. If the scroll map shows people stopping before the enquiry form, move the form or shorten what precedes it and watch whether the pattern changes. If clicks land on something that is not clickable, either make it a link or remove the styling that promised one. Pair the map with session recordings for the reason behind the behaviour, check what people actually see above the fold on their own phone, and feed what you learn into ordinary conversion rate optimisation work rather than redesigning on the strength of one colourful image.