Free online mouse scroll test
Scroll Wheel Test
Test your mouse wheel in both directions. Watch scroll counts and direction changes, then check any unexpected reverse scrolling.
Keep your pointer in the scroll area. Start with free scrolling, or choose a one-direction check to investigate a problem.
Scroll up and down freely. Direction changes are recorded without warnings.
Scroll here · middle-click the wheel
What does the mouse scroll test check?
This scroll wheel test records upward and downward wheel input received by your browser. Use Free scroll to check both directions, or One-direction check to investigate a wheel that seems to jump back while you are scrolling steadily. Press the wheel to check middle click as well.
Free scroll: check both directions
Scroll up, then down. The counters and direction history update with each received event. Changing direction is expected in this mode and does not produce a reverse-input warning.
One-direction check: investigate reverse scrolling
Scroll steadily in one physical direction. After three same-direction events establish the expected input, an opposite event is marked for review. Only treat it as unexpected if you did not reverse your finger’s movement; reset before testing the other direction.
Wheel events are not physical notches
The count shows events sent to the browser, not the exact number of wheel detents you felt. Trackpads and free-spinning wheels can produce different patterns. Compare the direction and consistency of input rather than expecting one event for every notch.
Reading your scroll wheel results
Use the direction history to see what arrived and the counters to compare repeated inputs. The page cannot count a physical wheel movement that never reached the browser.
- Scroll UpeventsReceived upward wheel inputs
- Scroll DowneventsReceived downward wheel inputs
- Middle ClickbuttonWhether a wheel press was received
- Direction TrailhistoryThe latest 32 scroll directions
- Opposite InputreviewA direction change in One-direction check
- deltaYvalueThe latest vertical wheel-event value; units depend on the browser event
How to test your mouse scroll wheel
Keep the pointer inside the scroll test area. Start in Free scroll mode.
Roll the wheel up and down separately. Confirm that each direction updates its counter and appears in the direction history.
Press the wheel down once to test middle click. Wheel rotation and wheel clicking are separate inputs.
If scrolling seems to jump back, select One-direction check for a fresh run and keep rolling steadily in one direction.
Review any opposite-input message against your own movement. Reset before reversing direction or comparing another mouse.
Frequently Asked Questions
- Note
Why does my mouse scroll the opposite way?
If the direction is consistently opposite to what you expect, check the system’s natural scrolling or inverted scrolling setting. If it changes briefly during a steady one-way roll, repeat One-direction check to see whether the pattern recurs.
- Note
Why is my scroll wheel jumping up and down?
Compare your steady physical movement with the recorded arrows. Repeated opposite events warrant checking the device and its settings, but this page cannot diagnose an encoder fault. Try another browser and compare a second mouse.
- Note
Why is the scroll wheel not working here?
Make sure the pointer is inside the test area. If no count changes, check whether scrolling works in another page or application, then inspect your device connection and scroll settings. The test only displays input it receives.
- Note
Can I use this with a trackpad?
Yes, a trackpad can send wheel events and update the direction history. That checks trackpad scrolling; it does not test a physical mouse wheel or its middle-click switch.
Related tests
Use Mouse Button Test for a wheel button that releases early, or Double Click Test for extra wheel clicks.