MOUSE SCROLL TESTER

Free-spin wheels on mice like the Logitech G502 X or MX Master can spin freely for seconds after a flick, generating thousands of scroll events. Notched wheels produce one discrete event per click and are physically limited by how fast your finger can flick. A free-spin mouse can produce 10–20× the score of a notched wheel.

Pixels per second (px/s) is calculated by summing all event.deltaY values from wheel events in a 500ms sliding window, then dividing by 0.5. This gives you a rolling velocity measurement rather than a point-in-time snapshot. Peak speed is the maximum this value reached during your test. The Sensitivity setting multiplies each deltaY before accumulation.

Scroll speed naturally varies with muscle fatigue, warm-up state, wrist angle, and OS scroll settings. For consistent results: let your mouse settle at room temperature, close background apps to reduce CPU load, and always run 3+ tests and take the best one. Free-spin mice are particularly variable due to their flywheel dynamics.

Target detection checks whether the target row's centre crosses the visible viewport area of the arena. If you scroll too fast, the row may pass through the detection zone between animation frames. Try scrolling slightly slower through each target row, or use a longer test duration. The arena height also matters — taller zones give more detection time per frame.

Your scroll events are grouped into chunks of ~15. For each chunk, the average speed is computed. The standard deviation of these chunk speeds is then divided by the overall mean to produce the coefficient of variation (CV). Consistency = (1 - CV) × 100%. A steady, unvarying scroll gives 90%+. Bursting then stopping drops it below 50%.

This tool stores all data locally in your browser's localStorage — nothing is sent to any server. To share results, use the Export CSV button and share the file manually. When comparing with others, always note the mouse model and OS scroll settings, as these dramatically affect scores.

Use the "Clear History" button in Settings to delete all saved sessions. Use "Clear All" in Keyword Manager to remove keywords. Settings can be reset with "Reset Defaults". To fully wipe everything open browser DevTools → Application → Local Storage and delete all keys starting with "scroll_".

In Rhythm mode, a target BPM defines an expected interval between scroll events (e.g. 80 BPM = 750ms between events). Each wheel event is compared to the nearest expected beat time. The deviation (in ms) is measured and averaged. Accuracy = max(0, 100 - avgDeviation / targetInterval × 100). Perfect timing gives 100%, scrolling randomly gives near 0%.