A stethoscope for your mouse wheel
Mouse Scroll Test is a free online scroll wheel test. Scroll for a few seconds and it grades your wheel's health from 0–100, flags reversed ticks and dead notches, and produces a diagnostic report you can act on — clean the encoder, or replace the mouse before it fails mid-project.
What it measures
Wheel speed, DeltaY peaks, DeltaMode, reverse spikes, stroke consistency, notch coverage and encoder class — fused into a single 0–100 Wheel Health Score with a plain-English verdict.
How it works
The tool listens to the wheel events your browser already receives and analyses their direction, timing and magnitude. Mechanical encoder faults — dust, oxidation, contact bounce — leave fingerprints in that signal.
Why it is trustworthy
Everything runs locally in your browser. No installs, no accounts, no uploads: your scroll data never leaves your device, and there are no ads or trackers.
Our principles
100% browser-based
No downloads, no drivers, no permissions. If your browser can scroll a page, it can test your wheel.
Private by design
Results live in your browser only. We do not see, store or sell your test data — see the privacy policy.
Honest numbers
Every metric is documented in the metrics guide, including what a healthy value looks like and what a bad one means.
Free forever
The full test, report and history are free with no account. The site is ad-free, and we intend to keep it that way.
Suspect your wheel is skipping?
A 30-second scroll is enough for a first verdict. Test before you buy a replacement.