Watch your scroll direction.
A guided check of the input events that reach this browser.
Choose one intended direction, start, and scroll inside the pad in that direction for at least 5 vertical events. Pause between runs. Touchpad momentum can change what you observe.
A canceled or interrupted run does not establish a hardware problem.
What reached the browser
0 events · 0 opposite-direction events · totals by unit: {}
Cannot judge yet
No completed run yet. Untested inputs are not failures.
Observations describe this browser session. They do not certify hardware health. Read the method and next steps →
If the wheel scrolls the wrong way
You scroll in one direction but the page jumps the other way. This check counts wheel events whose vertical movement opposes the direction you chose, and keeps pixel, line and page units separate because they are not interchangeable.
A hardware cause and an ordinary cause look the same
Opposite-direction events can come from an encoder misreading a notch, from touchpad momentum carrying past a pause, or simply from a “natural scrolling” setting in your operating system. That is why the check reports browser wheel events, not physical wheel notches, and asks you to pause between runs.
How to read your result
- Not observed: no opposite-direction events in your completed runs.
- Needs another check: opposite-direction events appeared once; repeat with pauses between scrolls.
- Observed in more than one run: reverse events repeated in the same intended direction this session.
- Cannot judge: fewer than five vertical events, or an interrupted run.
What your shareable report shows
Your exported report records your intended direction, the count of opposite-direction events, the totals kept separately by unit, your browser and operating system, and whether it reproduced across runs.
If it reproduces, what to do next
- First rule out software: check whether “natural” or reversed scrolling is enabled in your operating system or mouse utility, then repeat the check.
- Repeat in a different browser and, if possible, on another computer or with a wired connection to rule out momentum and wireless dropouts.
- If reverse events still reproduce after that, keep your exported report and review the manufacturer’s warranty or return window. The browser observation documents the behavior; it is not a defect certificate.
These steps are general guidance, not a diagnosis. A browser check documents what happened in this session — the manufacturer confirms a physical fault. See the full method → See the open data →
Use a result as a starting point
If an unexpected event repeats, try a fresh browser session and another port or device where practical. Compare the same steps. A result can depend on the browser, operating system, input settings and physical device.
Does this measure hardware latency or polling rate?
No. Browser event delivery is affected by scheduling and input processing. These tools do not certify hardware latency, USB polling rate, DPI accuracy or switch lifespan.
Where do my results go?
The last 30 runs stay in this browser’s local storage. Use the history button to copy a readable report, export JSON or remove them. Raw keyboard and pointer event streams are not sent to a server by this app.