IInputChecks

Free browser diagnostic

Scroll Wheel Test

Check your mouse wheel for unexpected reverse scrolling and inconsistent input—right in your browser.

Live input diagnostic

Test your scroll wheel

Choose a direction, then scroll inside the test area. We look for unexpected reverse input.

For a physical wheel check, use a mouse rather than a trackpad.

Choose a direction:
For the best results, open this test on a computer with a physical mouse.
Choose a direction to beginScroll inside this areaYour browser stays on this page while you test.
Total Events0
Expected0
Reverse Events0
Reverse Rate0.00%
Longest Gap0 ms
Event Rate0 events/sec
Scroll Signal Green = selected direction · Red = reverse
Ready when you areChoose a direction, then scroll inside the test area.

How to Use the Scroll Wheel Test

Pick the direction you want to test, place your pointer inside the test area, and roll the wheel steadily for five to ten seconds. The live signal graph shows each recorded event, while the counters make opposite-direction input easy to spot.

What Does a Scroll Wheel Test Detect?

This tool compares the sign of each wheel event with the direction you selected. It can reveal browser-visible reverse events, pauses between events, and an inconsistent signal pattern. It does not measure physical wheel notches or diagnose hardware directly.

Why Does My Mouse Wheel Scroll the Wrong Way?

An occasional jump in the wrong direction can come from debris around the encoder, normal wear, a driver or accessibility setting, low wireless power, or a problem limited to one app. Start by repeating the test, then try another browser or computer. Read more about a mouse wheel scrolling the wrong way.

What Is Scroll Wheel Jitter?

Jitter is a signal that flickers or skips while you make one continuous motion. In practice it can feel like a page bounces up and down, jumps over a line, or briefly reverses. A red segment in the graph means the browser received input opposite to the selected direction.

Why Does My Mouse Wheel Jump Up and Down?

Try clearing surface dust, reconnecting the mouse, changing the USB port or receiver position, and testing without mouse utility software. Our guide on mouse wheel jumping walks through a sensible order of checks.

How to Troubleshoot a Glitchy Scroll Wheel

  1. Run the test two or three times using steady movement.
  2. Test the mouse on another browser and, if possible, another computer.
  3. Reconnect a wired mouse or refresh the battery and receiver connection.
  4. Check system scrolling and mouse software settings.
  5. Clean around the wheel carefully according to the manufacturer’s guidance.

Can This Test Tell If My Mouse Is Broken?

It can only report the input received by this page. Repeated reverse events are a useful clue, but they are not proof of a hardware failure. Compare results across software and devices before repairing or replacing anything.

◉Mouse TestCheck buttons, wheel and movement.⠿Double Click TestSpot unexpected repeat clicks.⌁Polling Rate TestEstimate input event frequency.

Frequently asked questions

Can this test tell if my mouse is broken?

No. It reports the wheel events that your browser receives, not the physical condition of the mouse. Repeat the test and try another computer before reaching a conclusion.

Why does my wheel scroll the wrong way?

Dust, wear, software settings, a loose wireless connection, or an application-specific issue can all lead to apparent reverse input.

Does this work with a trackpad?

Trackpads can send wheel events too, but use a physical mouse when you are diagnosing a mouse wheel.