A CPS test sounds trivial: count clicks, divide by seconds. Getting it right in a browser, on every mouse, phone and tablet, takes a few decisions. Here are the ones we made.
The timer starts with your first click
There is no countdown and no start button. The first press inside the box starts the clock and counts as your first click, so your reaction time is not part of the score. Presses after the time runs out are ignored.
Each click is timed with the browser’s high-resolution clock the moment the browser hands it to the page. The chart is redrawn once per screen frame, but the counting does not wait for frames, so a 60 Hz screen does not cap your score.
What counts as a click
- Mouse: every press of a mouse button inside the box. In the standard test any button counts; in the Right Click Test only the right one does.
- Touch: every finger that lands on the box counts separately. That is why the fastest records are set on tablets, with several fingers of both hands.
- Pen: each tap of the pen counts once.
- Keyboard: with the box focused, Space and Enter count as clicks. Holding a key down does not repeat.
Why we do not use pointer events for mice
Modern browsers offer “pointer events”, which merge mouse, pen and touch into one stream. They are usually the right tool. For a CPS test they are not.
The pointer events standard sends a pointerdown only when the first button goes down. If another button is pressed while the first is still held, as happens when you press the left and right buttons at once, the browser does not send a second pointerdown. A test built on pointer events silently drops those presses.
So the test listens to the older mousedown event, which fires for every button press, and uses touch events for fingers. Pens are the only input read through pointer events.
What your mouse reports is what counts
Mouse switches wear. An old switch can “bounce” and report one press as two, and some mice filter presses so heavily that drag clicking hardly works. From one test we cannot tell a bounce from a very fast finger, so the test counts exactly what your mouse reports. If your score suddenly jumps with an old mouse, the switch may be part of the reason.
The two lines on the chart
- The green line is your average so far: clicks divided by the time since your first click. At the end of the test it equals your score.
- The red line is your speed over the last 0.3 seconds, turned into a per second figure and lightly smoothed. It shows the bursts, the tired patches and the final push.
A steady rhythm gives a flat red line. An auto clicker gives a line that is too flat: human rhythm always wobbles.
Leaderboard runs get a second look
If you sign in and compete, the timings of your clicks go to our server with the score. We check that the clicks came from real input events rather than a script, and that the gaps between them look like a hand rather than a metronome. Scores of 20 CPS or more wait for a video before they are ranked.
Your personal records stay in your browser. Apart from leaderboard runs, each finished test sends us only an anonymous summary (length, clicks, device type) for the statistics.