Test your scroll speed and direction
Scroll inside the pad. See the direction, event count and signed wheel delta, then compare another run.
Scroll your wheel or trackpad here
Ready. Nothing is uploaded.
Event trace
Recent events appear here. Export keeps the full capture until the capture limit is reached.
Why are the units different?
A wheel event can report pixels, lines or pages. Each row keeps its original unit; deltas in different units are never added together. Up and down reflect the sign of the vertical delta, and horizontal input is shown separately.
What this browser can measure
Events per second measure what reaches this page. Trackpad inertia and browser settings affect the result; it is not a physical wheel-speed or health measurement. See the event and timing rules.
Try the related task
- Mouse test: Press each mouse button and see down, up and repeat events immediately, with honest limits on hardware diagnosis.
- Polling rate test: Move your mouse to see live, average and peak event rates, with the browser and OS limits stated beside the result.
- Double-click test: See every browser click and its interval, flag suspicious repeats, clear the run, and learn what this test cannot prove.