Mouse lab
Mouse scroll wheel test
Observe wheel direction, vertical and horizontal deltas, and the browser-reported delta mode.
How to use this check
Start, then use a physical mouse inside the outlined area. Button numbers follow the browser mapping. Touch input is not counted as mouse input.
What the browser measures
Marks show recorded events in sequence. Empty graphs mean no matching events have been observed.
Reading the result
Scroll one step at a time in each direction. A change of delta sign is an observed reversal. Smooth scrolling, touchpads and software can generate multiple events; event counts are not physical notch counts.
Why results can differ
A browser observes events exposed by your operating system. One test cannot establish whether a device is faulty. Connection, settings, focus and browser behavior can change the results.