Pointer velocity and acceleration vary physically
Physical variation over a sufficient sample.
What a detector infers
Velocity, acceleration reversals, direction changes, and timestamp quantisation catch constant-speed curved automation missed by linearity. It remains unscored.
How to resolve it
Use only as one feature in a validated model.
Nearby checks in Input & behaviour
- A move only reports a button down after that button was pressed
buttons-without-pressMouseEvent.buttons on a move reports which buttons are held, and a button can only be held after it has been pressed. - The pointer never crossed a long distance in one report from rest
pointer-jump-from-restWhen a hand starts moving a mouse that has been still, the first reports cover a few pixels each as the movement builds up. - The pointer came to rest on a control before pressing it
settle-before-pressA person brings the pointer onto a control and presses after it arrives: the hand has to stop, and then the finger has to act. - Pointer path curves the way a hand moves
pointer-path-linearityThe check captures the pointer path across the pad and measures two things about its geometry: the RMS perpendicular distance of every… - Pointer events arrive on hardware time
pointer-event-cadenceWhere the linearity check reads the path's shape, this one reads its clock. - Pointer samples arrive batched the way a hardware device delivers them
input-coalescing-vs-hardwareChrome delivers pointermove once per display frame and folds every hardware report that arrived in between into getCoalescedEvents()… - Movement deltas agree with the coordinates they were derived from
pointer-movement-delta-coherenceEvery pointer event carries two independent accounts of the same displacement. screenX and screenY are where the pointer is; movementX and… - Keystrokes have dwell and flight time
keystroke-timing-distributionThe probe records only two timings per key: dwell, from keydown to keyup, and flight, from one key's release to the next key's press.
Clearcote is a browser built for fingerprint coherence
It is a Chromium fork, maintained by the same people who wrote this reference. It ships as a compiled browser rather than as a stealth script injected into someone else's — which is a description of how it is built, and is not an argument about how it behaves on this check.
This audit takes no position on how Clearcote scores on Input & behaviour checks, on this one, or anywhere else. It has no baseline corpus of other people's fingerprints to rank you against and no vendor scoreboard — nearly every check is self-referential, asking one browser the same question through two independent APIs and reporting whether both answers can be true at once. It runs identically on any browser, including ours. Run it on yours and read the result yourself.
See the other checks in Input & behaviour — the family pointer-kinematics belongs to.