How to use the mouse test
- Move your pointer into the test area. Right clicks, side buttons and scrolling won't affect the page while it's there.
- Press each button once: left, right, the wheel (middle click), and both side buttons. Each part of the diagram turns green once it has worked.
- Scroll the wheel up and down. The arrows above and below the wheel light up.
- To check for double clicking, click one button slowly 20 or 30 times. Every click should add exactly one to the count.
How the test works
Your browser numbers mouse buttons in every press it reports. The test reads that number, highlights the matching part of the diagram, and adds one to that button's count. Scroll events give a direction from the sign of their vertical movement.
For double clicks, the test stores the time of each press. When the same button is pressed again sooner than the threshold, that press is flagged. A human double click is a deliberate pair of presses, but a chattering switch makes contact twice within a few milliseconds, which is far faster than anyone clicks on purpose. The list under the counts shows the exact gap for each flagged press.
The test runs entirely in your browser. Nothing you click is sent anywhere.
Mouse button numbers
These are the button numbers browsers use, as defined in the web's UI Events standard. The test shows the same number next to each button.
| Number | Button | Usual action |
|---|---|---|
| 0 | Left (primary) | Select, click links |
| 1 | Middle (wheel click) | Open links in a new tab, autoscroll |
| 2 | Right (secondary) | Context menu |
| 3 | Back (side button) | Previous page |
| 4 | Forward (side button) | Next page |
Left-handed settings swap buttons 0 and 2 in your operating system, so the test will show them swapped too.
What the results mean
| What you see | Likely cause |
|---|---|
| A button never turns green | The switch is dead, or mouse software has remapped the button |
| Possible double clicks on one button | A worn or dirty switch that bounces (chatters) |
| A held button lights up and goes dark on its own | The switch loses contact while held, which breaks dragging |
| Only one wheel direction counts | A faulty scroll encoder, or a wheel mode in the mouse software |
More mouse tests
- Scroll wheel test: count notches and catch steps that go the wrong way.
- Mouse polling rate test: see how many times per second your mouse reports.
- Mouse DPI test: measure your real DPI with a ruler.
- CPS test: see how fast you can click.