Mouse wheel diagnostics

Scroll Wheel Test

Test your mouse scroll wheel online. Check scroll up and down, scrolling speed, horizontal scrolling, and detect skipping or unexpected wheel movements.

Runs locally in this page. Your scrolling is not uploaded or saved after refresh.

Scroll wheel tester

Direction, count, speed, skipping & horizontal scroll

● Events stay in this page

Roll the scroll wheel over this area

Scroll up and down to check direction and speed. Tilt the wheel, hold Shift while scrolling, or use a touchpad gesture to test horizontal scrolling.

↑ Scroll UpNot tested

Roll the wheel to test

↓ Scroll DownNot tested

Roll the wheel to test

← Scroll LeftNot tested

Tilt wheel · Shift + wheel · touchpad

→ Scroll RightNot tested

Tilt wheel · Shift + wheel · touchpad

Scroll speed test

Test duration5s10s30s

Roll the wheel over the pad above as fast as you can. The run counts every scroll, so it measures scrolling pace, not hardware health. Run data stays in page memory and is cleared on refresh.

Results appear here after a run.

Wheel delta

The raw values of your latest scroll as reported by the browser:

deltaY —deltaX ——

Notched wheels usually report small values like ±1 or ±3 per notch; touchpads and free-spinning wheels report many tiny values. A value sign that flips while you roll one way is the skipping signal tracked below.

Scroll Health

Not tested Start scrolling to check for skipping and reverse events.

About scroll speed About skipping detection Buttons & basic wheel check

This test needs JavaScript.

Your scrolling cannot be measured without a script running. You can still read how to test your scroll wheel, what the test checks, and the FAQ below.

Speed

Scroll Speed Test

The tool shows two live speed numbers while you scroll: your current speed (scrolls in the last second) and your best speed in this session. For a controlled measurement, use the timed scroll speed test inside the tool: choose 5 / 10 / 30 seconds, press Start, and roll the wheel as fast as you comfortably can.

What a run measures

A run counts every scroll during the selected duration and divides by the time. The final number is scrolls per second, plus your best 1-second burst inside the run.

Device matters

A notched wheel, a free-spinning wheel, and a touchpad produce very different scroll rates. Compare your scores on the same device only.

Speed is not health

A fast or slow score says nothing about hardware faults. For skip and reverse detection, use the Scroll Health panel and the skipping test.

Diagnostics

Scroll Wheel Skipping Test

Scroll wheel skipping (also called a jumping or stuttering wheel) shows up as the browser receiving a brief movement in the opposite direction while you scroll steadily one way — for example a single scroll-up in the middle of a long scroll-down. The Scroll Health panel in the tool tracks exactly that.

How the detection works

After a few wheel movements in one direction, a single movement the opposite way that is immediately followed by more movements in the original direction is counted as a reverse event. Deliberate direction changes — where you keep scrolling the new way — do not match this pattern and are not flagged.

Scroll steadily down for 10–20 seconds, then steadily up. A healthy wheel typically shows No skipping detected; a worn one produces repeated reverse events.

The exact thresholds are described on the methodology page. They are an observational signal, not a confirmed hardware verdict.

Skipping detected repeatedly?

Clean the wheel and the sensor slot, replug the cable or receiver, and retest on another computer before replacing hardware. If skipping survives all of that, the wheel encoder is likely worn — see why mouse wheels skip or jump.

Left & right

Horizontal Scroll Test

The Scroll Left and Scroll Right channels react to horizontal wheel input. Three common inputs trigger them: a tilting wheel pressed left or right, Shift + wheel scrolling, and touchpad horizontal gestures.

What is covered

Both horizontal directions are tracked separately, with their own scroll counts, so one side failing is immediately visible.

What is not covered

This is a browser-level check. It cannot tell a physically tilting wheel apart from Shift + wheel or a touchpad gesture — all three arrive as the same kind of horizontal scrolling.

Quick start

How to Test Your Mouse Scroll Wheel

This free scroll tester needs no download and no setup. Three steps are enough for a basic mouse scroll wheel test.

Move over the pad

Place the pointer over the wheel diagram. The page does not scroll there; your scrolling feeds the test instead.

Scroll up, down, and sideways

Roll the wheel both ways, then tilt it or hold Shift and scroll. Each detected direction lights up with its own count.

Read the results

Check direction, speed, and the raw wheel delta, then look at Scroll Health for reverse events and run the timed speed test if you want a score.

Scope

What Does the Scroll Wheel Test Check?

The tool observes the scrolling your browser reports — nothing more, nothing less. It checks five things:

Check	What you see
Scroll up / scroll down	Whether each vertical direction registers, with separate scroll counts.
Scroll speed	Current and best scrolls per second, plus an optional timed run.
Unexpected direction changes	Isolated reverse events while scrolling one way — the skipping signal.
Horizontal scrolling	Scroll Left and Scroll Right channels from tilt, Shift + wheel, or touchpad input.
Wheel delta	The raw deltaY / deltaX values of the latest movement and the unit the browser reports it in (pixel, line, or page), to judge whether the input looks normal.

Not covered here

Polling rate lives on the mouse polling rate test. Click speed has its own dedicated test. Button checks and a basic wheel-response check live on the mouse test page.

Troubleshooting

Why Is My Mouse Wheel Skipping or Jumping?

A wheel that skips, jumps, or scrolls the wrong way usually has one of five causes. Work from the cheapest fix to the most expensive.

Cause	What to try
Dust and debris	Compressed air into the wheel slot and a careful wipe of the axle. The most common fix.
Worn encoder	Age degrades the wheel's optical or magnetic encoder. If reverse events persist after cleaning, the encoder is the prime suspect.
System scroll settings	Check lines-per-notch and smooth-scrolling options in your OS. Software changes how scrolling behaves, not whether the wheel skips.
Browser or app behavior	Test in another browser or app. If skipping only appears in one program, the cause is usually that program's scroll handling.
Wireless connection	Low battery, interference, or a far receiver can drop or corrupt reports. Replug the receiver, charge or replace the battery, retest wired.

Skipping often precedes other failures

A wearing wheel can start skipping before clicks begin double-firing. If you also notice one press registering twice, run the Double Click Test and themouse double-clicking guide.

Scroll wheel test FAQ

How do I test my mouse scroll wheel?

Roll the wheel over the test pad on this page. Scroll Up, Scroll Down, Scroll Left, and Scroll Right are tracked separately, and the live panel shows direction, speed, and the raw wheel delta of your latest scroll.

How do I test my scroll speed?

Use the scroll speed test inside the tool: pick a duration, press Start, and scroll as fast as you comfortably can. The result shows your total scrolls and scrolls per second for the run. Compare speeds on the same device only.

What is scroll wheel skipping?

It is when the wheel reports a brief movement in the opposite direction while you scroll steadily one way — for example an isolated scroll-up event while you keep rolling down. This page tracks those reverse events in the Scroll Health panel.

Does a skipping warning mean my mouse is broken?

No. It is an observation, not a verdict. Scroll steadily in one direction for at least 10 seconds and retest. Skipping that repeats after cleaning the wheel and retesting on another computer points to a worn encoder; see why mouse wheels skip or jump.

How do I test horizontal scrolling?

The Scroll Left and Scroll Right channels react to a tilting wheel, Shift + wheel scrolling, and touchpad horizontal gestures. If one direction never responds, check whether the app or system maps horizontal input before assuming a hardware fault.

Why do my counts look very high on a touchpad?

Touchpads and free-spinning wheels send many tiny scroll signals for the same finger movement, while notched wheels send fewer, larger ones. Counts and speeds are comparable only on the same device and input method.

Why does nothing happen when I scroll?

Keep the pointer over the test pad while scrolling — the page does not scroll there, your scrolling feeds the test instead. If a direction still never responds, try another browser or computer and check system scroll settings.

Is this the same as the mouse test page?

No. The mouse test only checks whether scroll up and down register at all. This page is the dedicated wheel diagnosis: direction counts, speed, skipping and reverse events, and horizontal scrolling.