DPI Deviation Test – Check Mouse Sensor Consistency
Deviation mode isolates sensor consistency: move your mouse the same distance several times and see how much the estimated DPI varies. Low variation means a healthy, consistent sensor (and technique).
Setup
Consistency test
Consistency results
Verdict: Run the test to get a verdict.
Per-trial DPI
| Trial | DPI (est.) | Diff from mean |
|---|---|---|
| No trials recorded yet. | ||
How to read the results
- Mean DPI — the average of your trials.
- Standard deviation — how far trials typically spread from the mean, in DPI.
- CV (coefficient of variation) — standard deviation divided by the mean, as a percentage. CV under 3% is very consistent; under 7% is typical for a human; above 7% suggests technique or hardware issues worth investigating.
What high deviation usually means
Before suspecting the sensor, suspect the technique: curved swipes, varying speed (acceleration still on?), a dirty or reflective surface, and lifting the mouse all inflate variation. Re-test with slow, deliberate, straight swipes. If CV% stays high across careful re-tests, the sensor may be aging or the surface may be unsuitable — a dedicated mousepad helps. The main DPI analyzer also has a deviation mode with a movement-path chart for diagnosing technique problems.
Frequently asked questions
What is a DPI deviation test?
It measures how much your estimated DPI varies across identical swipes. Each trial gives a DPI estimate; the tool reports the mean, standard deviation, and coefficient of variation (CV%) so you can see whether the sensor — and your technique — are consistent.
What is a good CV% for mouse consistency?
Under 3% is very consistent, under 7% is typical for a careful human on a good surface, and above 7% usually means technique or hardware problems worth investigating.
Does high deviation mean my mouse is broken?
Not necessarily. Technique issues (curved swipes, varying speed, acceleration left on, bad surface, lifting) are the usual cause. Re-test carefully before suspecting the sensor.
How is this different from the main DPI analyzer?
The main analyzer focuses on estimating your DPI across trials with charts, export, and history. This page isolates consistency: per-trial comparison with a plain-English verdict.
How many trials should I run?
Five trials is a good default. Three is quicker but noisier; ten gives the most reliable verdict at the cost of time.
Do I need to disable mouse acceleration?
Yes. Pointer acceleration makes movement non-linear with speed, which directly inflates deviation. Turn off “Enhance pointer precision” in Windows first.
Can I run this on a laptop touchpad?
No. The test needs the raw, repeatable movement of a physical mouse. Touchpads apply their own acceleration and gesture handling.
What surface gives the most consistent results?
A clean, non-reflective mousepad of uniform color. Glass and highly reflective surfaces cause tracking noise that shows up as high deviation.