Ready to test

Ready

Start the test, place your pointer over the area, and scroll up or down to trace the line graph.

Scroll here to draw the line graph

Latest direction

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deltaY

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Delta mode

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Wheel events

Direction changes

Possible opposing impulses

Waiting

The latest wheel events
Direction	deltaY	Mode
No events recorded yet.

How to read the result A possible opposing impulse is only a pattern in the browser events. It is not proof that your mouse is defective.

What this tool does

Inspect the direction and raw values produced by a mouse or trackpad wheel.

Spot rapid opposing wheel events without sending the measured data anywhere.

How to use the tool

Start the test and place the pointer inside the highlighted test area.
Scroll up or down and compare the line graph with the latest event values.
Use the event history to review the most recent wheel events and their delta modes.
Reset the test when you want to begin a fresh local measurement.

Wheel delta values and delta modes are supplied by the browser and can differ between devices and operating systems.
A rapid opposing impulse is a neutral event pattern, not a reliable hardware diagnosis.
The test area blocks page scrolling only while it is active and receives the wheel event.
All measurements are kept in the current page and are discarded when the page is closed or reset.

Does the test upload my wheel data?

No. The events are processed locally in your browser and are not sent to petuja.tools.

Why do different devices show different delta values?

Browsers expose device input using different delta sizes and modes, especially for wheels, trackpads and high-resolution scrolling.

Is a possible opposing impulse proof that my mouse is broken?

No. It is only a pattern in the browser events and should be checked together with the physical behavior in other applications.

Why does the page not scroll inside the test area?

The active test area temporarily consumes its own wheel events so that the visualization can inspect them without moving the page.

What does deltaMode mean?

It tells you whether the browser reports delta values in pixels, lines or pages.