A mouse button that sometimes does not register is easy to miss until it ruins a game or a document. A few minutes with an online tester tells you whether the problem is the mouse.

Step-by-step

  1. Open the mouse test.
  2. Press each button in turn: left, right, middle (the wheel click) and any side buttons.
  3. Check that the matching on-screen button lights up and the counter goes up by exactly one per press.
  4. Press each button 10 to 20 times at different speeds.

What the results mean

  • Button lights up every time: it is working.
  • Misses presses: possible dirt, wear or a loose connection.
  • Counts twice: likely switch chatter. Follow our guide to checking for double clicking.
  • Side buttons do nothing: they may be remapped by your mouse software to keyboard shortcuts, so the browser never sees a mouse event.

Check the scroll wheel too

Use the scroll test to see up and down events and spot a wheel that skips or only scrolls one way.

Browser limits

Some operating systems and browsers intercept buttons such as back and forward before a page can see them, so a missing side button does not always mean a fault.

Ready to put it into practice?

Run the free CPS test and see where you stand — no download, no sign-up.

Start CPS Test