# Scroll Test

> Free mouse scroll test: measure scroll wheel speed in steps per second, see up vs down counts, and check for a mouse wheel that skips or jumps. No download.

Test your mouse scroll wheel. This scroll test counts wheel notches per second, splits scrolling up from scrolling down, and helps you spot a worn wheel encoder that skips or scrolls the wrong way. Page scrolling is paused while your pointer is over the pad, so every notch is counted.

- **Live tool:** https://www.toolnova.org/diagnostics-tools/scroll-test
- **Category:** Speed Test & Diagnostics (https://www.toolnova.org/diagnostics-tools)
- **Price:** Free
- **Requirements:** Runs in a modern web browser · No signup · No install

## What this tool does

- Counts wheel notches per second, with separate up and down totals.
- Page scrolling is paused over the pad so nothing is lost.
- Handles pixel, line and page scroll modes from different mice and trackpads.
- Timed, target and endless runs with a live speed graph.
- Endless mode for slow, notch-by-notch checks of a faulty wheel.
- Saved bests and history on your device.

## How to use Scroll Test

1. **Move the pointer over the pad** — Scrolling inside the pad is captured and the page will not move.
2. **Check the wheel slowly first** — In Endless mode, scroll down one notch at a time. The down counter should rise by one each notch and the up counter should not move.
3. **Repeat upwards** — Scroll up notch by notch and check the opposite counter stays still.
4. **Run a speed test** — Choose a timed run and flick the wheel as fast as you can to see your scroll speed.

## Common use cases

- Diagnosing a mouse wheel that jumps, skips or scrolls the wrong way
- Measuring scroll speed for games that bind jump or actions to the wheel
- Comparing notched and free-spin wheel modes
- Checking a wheel after cleaning or repair

## About

### How to tell if your scroll wheel is faulty

A mouse wheel reports its movement through a small encoder. When the encoder wears or collects dust, slow scrolling in one direction can register as a jump the other way, or notches can be skipped. Scroll slowly in Endless mode and watch the up and down counters separately: in a healthy wheel only one counter moves at a time.

| Symptom | Likely cause | Try |
| --- | --- | --- |
| Scroll down sometimes counts as up | Worn or dirty encoder | Compressed air, then replacement |
| Several notches count as one | Smooth-scrolling driver or trackpad | Test with the mouse's driver off |
| Very large counts per notch | Page or line scroll mode | Normal, counts are normalised to steps |
| Nothing registers | Wheel disabled or remapped | Check mouse software |

### Scroll speed for gaming

Some players bind jump or weapon switching to the scroll wheel because spinning it fires many inputs quickly. Free-spinning wheels, found on some productivity and gaming mice, score far higher than notched wheels. A quick timed run shows how many inputs per second your wheel can deliver.

See also: [CPS Test (all modes)](https://www.toolnova.org/diagnostics-tools/cps-test), [Butterfly Click Test](https://www.toolnova.org/diagnostics-tools/butterfly-click-test), [Jitter Click Test](https://www.toolnova.org/diagnostics-tools/jitter-click-test), [Drag Click Test](https://www.toolnova.org/diagnostics-tools/drag-click-test), [Mouse Polling Rate Test](https://www.toolnova.org/diagnostics-tools/mouse-polling-rate-test)

## FAQ

### How do I test my mouse scroll wheel?

Put the pointer over the pad, switch the run to Endless and scroll one notch at a time in each direction. Each notch should add one to the matching counter only.

### Why does my scroll wheel jump the wrong way?

The wheel encoder is usually worn or dirty. Compressed air can help for a while, but the lasting fix is replacing the encoder or the mouse.

### Does it work with a trackpad?

Yes, but trackpads send smooth pixel scrolling, so step counts are estimates and not comparable with a notched mouse wheel.

### Why doesn't the page scroll while I test?

Scrolling is paused while your pointer is over the pad so every wheel step is counted. Move the pointer off the pad to scroll the page.

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