Smoothness Test
Draw lines on the canvas to inspect your mouse sensor's raw tracking output. Jagged edges, straightened diagonals, and stepped curves each indicate specific hardware behaviors — revealed live by plotting your actual coordinate stream.
- Click and drag slowly across the canvas to draw a line.
- Attempt a slow diagonal line — check if it appears perfectly straight.
- Attempt a gentle curve — check if edges are smooth or stepped.
- Draw a very slow line to test for sensor smoothing artifacts.
Angle snapping forces diagonal lines to snap to flat horizontal/vertical planes. To detect it: draw a 30° diagonal slowly. If the resulting line is perfectly flat, your firmware is applying angle snapping — turn it off in mouse software.
What This Test Measures: Sensor Tracking Linearity
This test plots the raw coordinate stream from your mouse sensor directly onto a canvas — every X/Y position event your browser receives is drawn in real time. What you draw is literally the data your sensor is sending to your computer, with no smoothing or interpolation added by the test. Plotting your mouse coordinate stream helps spot sensor noise, which you can cross-reference using our complete mouse diagnostics.
This lets you visually inspect three specific sensor behaviors:
- Angle snapping: Firmware that forces diagonal movements toward flat horizontal or vertical paths. Shows as perfectly straight lines when you intended a shallow diagonal.
- Sensor smoothing: Firmware that averages nearby coordinate samples, rounding sharp corners and lagging behind fast movements. Shows as lines that feel "sticky" or rounded at direction changes.
- Tracking jitter: Random noise in the coordinate output from the sensor's optical system. Shows as jagged edges on slow, controlled movements.
These signals are captured live from your browser's pointermove event — the actual coordinates your mouse hardware is reporting right now, on this page.
How to Read Your Smoothness Result
- Clean diagonal lines at 30–45°: No angle snapping. Good.
- Diagonal lines appear flat/horizontal: Angle snapping detected. Disable in mouse software.
- Curves have visible stair-stepping at slow speeds: Normal — low-resolution DPI setting. Increase DPI or this is the natural sensor step resolution.
- Lines at slow speed appear consistently jagged: Sensor jitter or poor surface tracking. Try a different mouse pad texture.
- Lines lag behind your hand movement visually: Sensor smoothing or prediction is active. Disable in manufacturer software.
What Causes Poor Smoothness Readings
- Angle snapping firmware: Many mice enable this by default to help with horizontal/vertical scrollbar interactions. In gaming, it destroys diagonal tracking accuracy. Disable in mouse software under "Angle Tuning" or "Line Correction."
- Sensor smoothing / prediction: Some sensors add a prediction algorithm that extends coordinate paths slightly ahead of physical movement to reduce perceived jitter. This creates lag in direction changes. Disable "Smooth" or "Motion Prediction" settings.
- Surface mismatch: Optical sensors are calibrated for specific surface textures. Extremely glossy, transparent, or uniform surfaces can cause the sensor to lose lock and produce jitter.
- Very low DPI setting: At 400 DPI or below, the sensor's native step resolution becomes visible as stair-stepping on slow movements. This is physics, not a fault.
How to Improve Sensor Smoothness
- Disable angle snapping and motion smoothing in your mouse software.
- Increase DPI to 800–1600 if you see stair-stepping at slow speeds — then adjust in-game sensitivity down to compensate.
- Clean your mouse pad — a dirty surface introduces jitter that looks like sensor noise.
- Replace worn mouse feet (skates) — drag inconsistency from worn feet introduces micro-pauses that show up as steps in the drawn line.
Want to understand whether your firmware is smoothing your raw coordinate path? Learn how to detect sensor smoothing and angle snapping in real cursor output — and check how worn mouse skates affect tracking accuracy on different surface types.
Draw a 20–30° shallow diagonal slowly. If the line appears perfectly flat and horizontal, angle snapping is forcing your coordinates to snap to the horizontal axis. Disable "Line Correction" or "Angle Tuning" in your mouse software.
Not exactly. Sensor jitter is random noise in the coordinate output — appears as jagged edges on slow lines. Cursor stuttering is frame-rate or polling-rate related — appears as the cursor jumping in visible steps. Both can show in this test but have different causes.
Yes. At low DPI (400 and below), the step resolution of the sensor becomes visible as stair-stepping on slow movements. This is physically normal — not a fault. Increase DPI to 800+ to eliminate this visual artifact.