Scroll Wheel Test
Diagnose wheel direction, jumps, reverse events, and short-window event rates without converting to physical RPM.
Tests run locally in your browser. We do not upload keystrokes, pointer paths, or media.
Important
- Wheel deltas and rates are browser-reported. They are not physical RPM measurements.
Ready — choose a mode, then press Start
Counts are browser wheel events and delta values, not physical wheel notches or RPM. macOS Natural Scrolling can reverse the sign users expect.
Direction / event diagnostic
- Session
- Ready
- Browser wheel events
- 0
- Up / down direction
- 0 / 0
- Cumulative browser delta Y
- 0
- Last browser delta Y
- —
- Horizontal browser events
- 0
- Middle button events
- 0
- Reverse hints
- Not evaluated
- Relative delta spikes
- 0
select Up only or Down only
>40 delta units (4× median, min 40)
Reverse hints are shown only against an expected direction and can reflect Natural Scrolling, inertia, or normal device behavior. Relative delta spikes compare browser-reported magnitudes within this session; they are not a hardware-fault verdict.
How to use
- Scroll vertically and horizontally over the test surface.
- Watch up/down/left/right counters, reverse hints, and large jumps.
- Optionally run a 5s, 10s, or 30s speed window for events per second.
- Middle-click the surface if you want middle-button counts.
What the result means
- Event counters reflect browser wheel events, not physical detents.
- Reverse hints mark consecutive deltaY sign flips.
- Speed scores are browser events per second during the timed window.
Limitations
- Delta units depend on the browser and input device (lines/pixels/pages).
- Results are never converted into physical RPM.
- Smooth-scroll devices emit many events per gesture.
Troubleshooting
- No horizontal events
- Not all mice expose horizontal wheel data. Trackpads often do with side gestures.
Related tools
Mouse Test
Check mouse buttons, hold stability, movement path, and basic wheel events using the browser Pointer Events API.
Double Click Test
Analyze click intervals and possible unintended double-clicks using configurable browser event thresholds.
Mouse DPI Test
Estimate mouse DPI using Pointer Lock movement counts across a known physical distance. Results are estimates only.
FAQ
Can you show RPM?
No. Browsers do not provide reliable physical rotation speed for mice.