Mouse Test — Buttons, Wheel and Tracking
Test every mouse button, the scroll wheel and cursor tracking in your browser. See which buttons your mouse actually reports and catch a failing wheel encoder or a side button that never fires.
What each part of the test checks
Buttons. Every physical button on a mouse sends a numbered event: 0 for left, 1 for middle, 2 for right, 3 and 4 for the two side buttons. The list above lights up as each number arrives. A button that never lights either has a failed switch or has been remapped to a macro in the manufacturer's software, in which case the browser never sees a standard button event at all.
Scroll wheel. The counter increases with each wheel event and shows the direction. Roll slowly and watch for two specific faults: a scroll that registers in the opposite direction to the one you turned, and a scroll that produces nothing for part of a rotation. Both point to a worn optical encoder inside the wheel assembly, which is the most common mechanical failure in a mouse after the left switch.
Tracking. Move the cursor slowly across the box and watch the coordinates. They should change smoothly. Jumps, freezes or coordinates that stop updating in one area of the desk are almost always a surface problem rather than a mouse problem.
Why surfaces matter more than people expect
An optical mouse works by photographing the surface underneath it thousands of times per second and comparing consecutive frames. It needs texture to compare. Glass has none, high-gloss desks reflect the illumination straight back, and plain white surfaces under certain lighting produce frames that all look identical.
The result is a cursor that stutters, jumps, or drifts while the mouse is still. Before replacing anything, put a sheet of ordinary paper under the mouse and repeat the test. If the problem disappears, the mouse is fine. Laser sensors handle difficult surfaces better than LED sensors, and dedicated glass-capable sensors better still, but even those prefer texture.
Also check the sensor lens. A single hair across it produces exactly the same symptoms as a failing sensor and takes two seconds to remove.
Wired, wireless and latency
| Wired USB | 2.4 GHz dongle | Bluetooth | |
|---|---|---|---|
| Typical polling | 125–8000 Hz | 125–1000 Hz | Around 125 Hz |
| Latency | Lowest | Very low | Noticeably higher |
| Interference | None | Possible from USB 3 ports and Wi-Fi | Possible, and more variable |
| Common issue | Cable fatigue at the strain relief | Dongle too far from the mouse | Reconnection delay after idle |
If a wireless mouse stutters, move the dongle to a front USB port or use a short extension cable to get it closer to the mouse. USB 3.0 ports are a well-documented source of 2.4 GHz interference, so a dongle sitting directly next to one often behaves worse than the same dongle a few centimetres away.
The most common mouse fault of all
By a wide margin, the failure people meet first is a left button that registers one press as two. It creeps in gradually, gets worse over months, and is maddening because it looks like a software problem. It is not — it is the switch contacts bouncing as they wear. Our double click test measures the gap between clicks in milliseconds and tells you definitively whether that is what is happening to yours.
More device tests
Microphone Test
Check that your mic is heard, at the right level, with no distortion.
Webcam Test
See your camera live, read its resolution and frame rate, take a snapshot.
Speaker Test
Left/right channel check, test tones and a full 20 Hz–20 kHz sweep.
Headphone Test
Verify both earcups, check stereo wiring and hear a frequency sweep.
Keyboard Test
Find dead, stuck or ghosting keys on a live on-screen keyboard.
Click Speed Test
Measure your clicks per second over 5, 10, 30 or 60 seconds.
Double Click Test
Detect a failing mouse switch that registers one click as two.
Dead Pixel Test
Full-screen solid colours that reveal dead and stuck pixels.
Mouse test FAQ
How do I test my mouse buttons?
Click inside the grey area with each button in turn. The matching zone on the mouse diagram lights up and the button appears in the list below. Side buttons register as back and forward if your mouse has them.
Why doesn't my side button register?
Browsers only receive side buttons when they are set to standard back and forward. If they are mapped to macros in the manufacturer's software, they never reach the page. Reset them to default in that software to test them.
My cursor jumps or stutters — what causes it?
Usually the surface. Optical sensors struggle on glass, gloss and plain reflective surfaces. Try a mouse pad or a sheet of matte paper first, then check for dust on the sensor lens, then try a different USB port.
What does the scroll counter test?
It counts wheel events and shows the direction. A wheel that skips, jumps back, or registers scrolls in the wrong direction has a worn encoder inside — a common failure after a few years of heavy use.
Is right-clicking on this page safe?
Yes. The test area suppresses the context menu so your right-click can be measured, and that only applies inside the grey box on this page.
Can I test a trackpad here?
Partly. Taps and two-finger scrolling register, but trackpad gestures are translated by the operating system before the browser sees them, so gesture support cannot be tested from a web page.
Is your mouse double-clicking on its own?
Measure the gap between clicks in milliseconds and find out whether the switch is failing.
Open the double click test