Mouse Button & Scroll Tester
Check every mouse button, both scroll directions and pointer movement.
Click every button here, scroll the wheel, and move the pointer around
The side buttons are drawn dashed because most browsers use them for Back and Forward and never pass them to the page. Not seeing them here does not mean they are broken.
How this test works
Click each button inside the pad, roll the wheel both ways and move the pointer around. Every button and scroll direction lights green once it has registered, and the pointer position is shown live so a sensor that stops reporting is visible immediately. Only left, middle and right count toward a complete result: the side buttons are optional hardware that most browsers claim for Back and Forward navigation, and horizontal scroll exists only on tilt wheels and touchpads, so scoring either would fail most working mice.
What the results mean
- Core buttons
- Left, middle and right — the three every mouse has. All three should register within a couple of clicks each.
- Side buttons
- The thumb buttons, if fitted. Drawn dashed because the browser normally uses them for Back and Forward and never passes them on. Not seeing them here is not evidence of a fault.
- Scroll wheel
- Up and down should both register. A wheel that reports one direction and not the other has a failing encoder.
- Movement events
- How many times the pointer reported a new position inside the pad. Zero while the buttons work points at the sensor or the surface.
Common problems and fixes
- The scroll wheel jumps back a line when I scroll down
- That is a worn wheel encoder sending a spurious pulse in the opposite direction. It gets worse over time. Compressed air around the wheel clears some cases; the rest are a replacement.
- The pointer stutters or jumps across the screen
- Clean the sensor window and try a plain opaque surface. Glass, mirrored and high-gloss desks defeat most optical sensors, and a mouse mat fixes it outright.
- My side buttons do not register
- Expected on most browsers — they are handled as Back and Forward before the page is told. Test them by browsing: if they navigate, they work.
- The mouse drops out for a second at a time
- On a wireless mouse, replace the battery and move the receiver to a front USB port away from USB 3 ports, which interfere with 2.4 GHz receivers. On a wired mouse, flex the cable near the plug while watching the movement count.
Frequently asked questions
How do I test if my mouse buttons work?
Click each one inside the pad above. Left, middle and right should each light green immediately. If one never registers, try the mouse on another computer before assuming the button has failed — a dead button in one machine and not another is a driver or a port problem.
Why does my scroll wheel skip or scroll the wrong way?
The wheel turns an optical or mechanical encoder, and as it wears it emits pulses in the wrong direction or misses them entirely. That shows up as scrolling that jumps back a line, or a wheel that needs two clicks to move one. Dust causes some of it and compressed air is worth trying, but a worn encoder does not recover.
Can this tell me my mouse DPI or polling rate?
No. Neither is exposed to a web page. DPI is set in the mouse firmware or its manufacturer software, and polling rate needs timing accuracy this test does not attempt. Anything claiming to read your DPI from a browser is inferring it from pointer movement, which your OS pointer-speed setting alters.