ApexCheckMouse & Trackpad
Record browser-visible wheel events to check reverse scrolling, skipped wheel steps, horizontal input, and recent scroll direction changes.
No scroll records
Start scrolling mouse wheel to view records
This page focuses on browser-visible wheel input: scroll direction, sudden reverse events, skipped-looking wheel steps, accidental horizontal scrolling, and whether the page receives a clear event when you move the wheel. It does not replace a hardware repair bench; it gives you a clean event record before you change drivers, clean the wheel, or test another mouse.
Do not judge the mouse from one unusual event. Scroll in one direction several times and watch whether the event log repeatedly shows the opposite direction. DeltaY is the vertical wheel signal, DeltaX is horizontal input, and DeltaMode only describes the browser's reporting unit. Repeated reverse direction is stronger evidence than one isolated spike.
The page listens to standard wheel events. Vertical movement is mapped from deltaY, horizontal movement from deltaX, and the recent log keeps the order in which the browser received each event. A web page cannot read the encoder, firmware debounce, private driver settings, dust, or physical wear inside the wheel.
A good scroll wheel test is about repeatable event patterns, not one dramatic number. Compare the same movement a few times and look for direction stability in the event log.
Usually normal
Worth checking further
Scrolling one way keeps producing the same direction in the log.
After you stop moving the wheel, no new wheel records appear.
Several quick scrolls still produce a readable sequence without repeated direction flips.
Scrolling down repeatedly shows up events, or scrolling up repeatedly shows down events.
New wheel records appear even though you are no longer touching the wheel.
Left or right wheel records appear when you did not use a tilt wheel or touchpad gesture.
Use the event log to decide whether you are seeing reverse scroll, skipped wheel input, horizontal input, or an app-specific scroll setting.
Wheel down sometimes jumps up
Scroll down several times in the test area and watch whether up events repeat.
If it repeats across browsers, clean the wheel gap or check for encoder wear.
The page scrolls by itself
Stop touching the wheel and watch whether the recent log keeps adding new entries.
Compare another mouse, receiver position, battery level, and driver settings.
Fast scrolling skips or cuts out
Make several quick scrolls and check whether the log has gaps or repeated opposite directions.
Try another USB port, remove hubs, charge the mouse, or move the wireless receiver.
Scrolling also moves sideways
Watch whether left or right records appear without an intentional sideways action.
Check tilt wheel, touchpad gestures, Shift scrolling, or system gesture settings.
Only one app scrolls badly
If this page looks stable, the cause is more likely inside that app or its shortcuts.
Check smooth scrolling, zoom shortcuts, extensions, game profiles, or in-app wheel bindings.
Q: Does one reverse event prove the wheel is broken?
A: No. Repeat the same one-direction movement and look for a pattern.
Q: Why does the page show horizontal scrolling?
A: Tilt wheels, touchpad gestures, Shift scrolling, and some drivers can create horizontal wheel events.
Q: Can this test a touchpad?
A: It can read touchpad wheel-like events, but a touchpad gesture is not the same as a notched physical mouse wheel.
Q: Is any data uploaded?
A: No. Wheel direction and recent events are used for the current page display.
If the log repeatedly shows the opposite direction while you scroll one way, clean around the wheel and retest with another browser or USB port. If the issue appears only in one app, check smooth scrolling, zoom shortcuts, extensions, game profiles, or in-app wheel bindings before replacing the mouse.