One image, one task, one click.

First-click testing shows a participant an image -- usually a screenshot or wireframe of a real page -- gives them a task, and records exactly where they click first, before anything else happens. Research popularised by Bob Bailey found a strong link between getting the first click right and completing the task overall, which is why this single click is worth measuring on its own.

No, but you get more out of the result if you do. Without a target area you still see every click plotted on the image, which is useful on its own -- a scatter of clicks nowhere near where you expected tells you something regardless of pass/fail. With a target area defined, the tool also calculates a first-click success rate.

A real screenshot or a static mockup of the page or screen you are testing. It does not need to be interactive -- the whole point is testing whether the STATIC design communicates where to click, before you build anything clickable. This tool takes an image URL rather than a file upload; most design tools give you a shareable image link in a couple of clicks if you do not already have one hosted.

A live-site heatmap (Hotjar and similar) shows you what real visitors already do on a page that exists, over time, across everyone. A first-click test is a small, deliberate experiment you run before or instead of shipping -- one task, a handful of participants, a specific question you chose. Use a heatmap to observe; use this to test a hypothesis before you commit to a design.