Mouse scroll test: check smoothness and polling rate

What the readings mean

• Bars: one for each scroll event the browser received in the last 3 seconds. The height is how far that one event moves the page, on a scale where 100 px sits halfway up.
• Events per second: how often scroll events arrive while you scroll. A notched wheel sends one per notch, usually well under 30 a second; a trackpad sends 60 or more.
• Typical step: the middle size of the steps in your last scroll. A notched wheel moves tens of pixels or more per step, a trackpad usually just a few.
• Scroll speed: pixels per second across your last burst of scrolling. Spin the wheel faster and macOS adds acceleration, so the steps grow too.
• Notched or smooth is a guess from the size and pattern of the steps. Browsers don't say which device scrolled, and a free-spinning wheel can look like a trackpad.

Why wheel mice feel choppy on a Mac

A trackpad sends dozens of tiny scroll events a second, and macOS keeps them coming for a moment after you lift your fingers, so the page glides. A regular wheel mouse sends one event per notch, and the Mac moves the page a fixed jump for each one. That is the row of tall, spaced bars in the chart, and it's why a page that glides on the trackpad stutters with a mouse.

macOS has no smooth scrolling option for wheel mice, and its scrolling speed slider covers every mouse at once. Scrollwise Pro ($2.99 once) turns each notch into a short glide and sets the scroll speed for each device on its own, so the chart here should show a run of small steps instead of a few tall ones. Fixing the scroll direction for each device is free.

Polling rate explained

Polling rate is how often a mouse reports its position to the computer. At 125 Hz it reports every 8 milliseconds, at 1000 Hz every millisecond. A higher rate makes the pointer follow your hand more closely, which matters most in fast games. For everyday work, 125 to 500 Hz feels fine, and Bluetooth mice often report less often than the same mouse on its USB receiver.

Browsers don't hand web pages every report. Most deliver pointer movement once per screen refresh and keep the samples in between in a list, which this test counts where the browser offers it. Some browsers drop or cap those samples, so the reading can land below the real rate, or at your display's refresh rate, such as 60 or 120. Treat it as an estimate and check the exact setting in the mouse maker's app.

Questions

Does this test send anything from my computer?

No. It reads scroll and pointer events in your browser, and nothing is stored or uploaded.

Why does my mouse wheel show big jumps instead of small steps?

Most wheel mice move in notches, and each notch arrives as one big scroll step. A trackpad, Magic Mouse or free-spinning wheel sends many small ones. On a Mac, Scrollwise Pro can turn the notches into smooth scrolling.

Is the polling rate reading exact?

No, it's an estimate. Browsers batch or cap pointer events, so it can read low, and a reading of 60 or 120 Hz is usually your screen's refresh rate. Chrome and Edge get closest because they share the samples between screen refreshes.

How do I change the scroll speed on a Mac?

Open System Settings > Mouse and move the Scrolling speed slider. That one slider covers every mouse; Scrollwise Pro sets a separate speed for each device.

How do I change my mouse's polling rate?

In the mouse maker's app, such as Logitech G HUB or Razer Synapse, or with a switch on the mouse itself. macOS has no polling rate setting of its own.