Mouse scrolling feels choppy on a Mac — measure it yourself
Scroll in each box below. This records exactly what macOS hands to software on every scroll event and draws both devices on one shared scale. The reason the wheel feels worse is visible in about two seconds.
Trackpad
waitingTwo-finger scroll inside the box. Flick and let go so the inertia gets recorded too.
- Distinct step sizes
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- Events
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- Events / second
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- Median step
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- Largest step
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- Decaying tail
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Mouse wheel
waitingSpin the wheel inside the box, about the same distance you just scrolled.
- Distinct step sizes
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- Events
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- Events / second
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- Median step
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- Largest step
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- Decaying tail
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What you are looking at
Each vertical line is one scroll event, placed by when it arrived and sized by how far it asked the page to move. Both panels use the same bar width and the same vertical scale, so the two shapes are directly comparable.
Distinct step sizes is the number that matters
A trackpad reports a continuously varying distance on every event, and keeps sending events after your fingers leave the surface. A wheel reports a fixed detent, over and over. Trackpads typically produce dozens of distinct values; wheels often produce exactly one.
That single number is the whole story. macOS has nothing to interpolate between when a wheel sends the same jump every time, so it moves the page in hard steps. Nothing is broken, and a more expensive mouse will not change it — it is what the hardware reports.
Method and limits
Recording uses the standard wheel DOM event. Each panel starts on your first event and stops after 500 ms of stillness. Values are what the browser exposes, which sits one layer above the raw device — macOS has already applied its own scroll handling, and browsers may coalesce events under load. Compare your two devices on one machine rather than comparing absolute numbers across machines.
Frequently asked questions
Why does my mouse scroll feel choppy on a Mac when the trackpad feels fine?
Because the two devices send fundamentally different signals. A trackpad reports a continuously varying distance many times per second, and keeps reporting after your fingers lift — that decay is the inertia you feel. A wheel reports the same fixed detent value every click, with nothing in between. macOS applies the wheel value directly, so the page moves in hard steps. The test on this page shows both signals on one scale.
Will a more expensive mouse fix choppy scrolling on macOS?
Usually not. The step size is a property of the wheel encoder, not of price. Some high-resolution wheels do report finer steps, and the test will show that as a higher distinct-step-sizes count. But most mice — including premium ones — report a single repeated value, and no amount of hardware spend changes how macOS interpolates it, because there is nothing to interpolate.
What does “distinct step sizes” mean?
It counts how many different scroll distances your device reported during one recording, after rounding to two decimals to discard floating-point noise. A trackpad typically produces dozens because every event differs slightly. A wheel often produces exactly one. That single number is the clearest summary of why the two feel different.
Is this reading my hardware directly?
No. It reads the standard wheel events the browser receives, which is one layer above the device: macOS has already applied its own scroll handling, and the browser may coalesce events under load. Absolute numbers therefore differ between browsers and macOS versions. The comparison between your two devices on the same machine is the meaningful result, not the raw magnitudes.
Which browsers does this work in?
All of them, including Safari and Firefox. The test only uses the standard wheel DOM event, so there is no WebHID requirement and no device permission prompt. Nothing is uploaded and nothing is stored — reload the page and the recordings are gone.
Can choppy wheel scrolling actually be fixed?
Yes, in software. The missing in-between frames a wheel never sends can be generated: each detent becomes a short eased animation instead of an instant jump. LinguaX does this for any USB or Bluetooth mouse on macOS 13+, with tunable Min Step, Speed Gain and Duration, a per-app on/off override, and the trackpad passed through untouched.