What Is Mouse Drift?
Mouse drift is unwanted cursor movement when your hand is not touching the mouse. It happens when the sensor imagines motion — reading micro-variations in the tracking surface as real movement and reporting them to the OS. A healthy gaming sensor should report exactly zero counts when the mouse is stationary. This tool measures that by listening to every PointerEvent the browser receives during a fixed idle window.
How The Drift Test Works
Each pointermove event gives us a new (x, y) in CSS pixels. We compare consecutive events, sum the Euclidean distance, track the largest single jump, and count the number of events. After 10-180 seconds we report:
- Total drift — sum of distances between consecutive pointer samples (px).
- Max single-event delta — the biggest jitter jump in one event (px).
- Pointer events recorded — how many moves the browser reported.
Zero pixels total = a perfectly still sensor. A couple of pixels over 60 seconds is normal electronic noise.
Laser vs Optical Sensors
Laser sensors (Philips Twin-Eye, older Razer) see fine surface detail, which is great on cloth but triggers false movement on glossy, painted, or highly reflective desks. Optical sensors (PixArt PMW3360, PAW3395, HERO) track contrast changes — they hate transparent glass mats and very dark surfaces. Matching the sensor to your mousepad eliminates 90% of drift reports.
When Drift Is A Real Problem
If the test reports more than ~25 px over 60 seconds on a proper mousepad with acceleration disabled, the issue is usually one of: a damaged sensor lens, outdated firmware, a sensor-smoothing bug in a gaming driver, or a failing USB cable introducing noise. Update the mouse driver, try a different USB port, then replace the mouse if drift persists.