Every raw pointer update carries at least its own sample
Every mouse pointerrawupdate's getCoalescedEvents() holds at least one sample. N/A outside secure contexts, on non-Chromium engines and when no rawupdate was observed (severity: warn).
What a detector infers
pointerrawupdate fires for each pointer report as it arrives, without waiting for the next frame, and Chrome builds each one from a real input event. When several reports are merged into one rawupdate, getCoalescedEvents() lists all of them; when there is only one, it lists that one. Either way the list holds at least the event itself: main_thread_event_queue.cc creates the rawupdate from an input event, and the coalesced list is built from the events merged into it.
A pointerrawupdate whose getCoalescedEvents() is empty therefore had no input event behind it — it was manufactured, between the real ones, by whatever is generating the input. Measured on genuine Chrome receiving input through the DevTools protocol: 82 of 82 rawupdates carried exactly one sample. The row needs a secure context, where pointerrawupdate exists, and a listener registered before input arrives.
High-polling-rate mice have not been measured yet; by the source they produce more samples per rawupdate, never fewer than one. Where input-coalescing-vs-hardware reports how many samples moves carry, this row asserts the one count that cannot occur: zero.
How to resolve it
Deliver input as input events through the browser's input pipeline, one per report, rather than synthesising extra pointerrawupdate events between them. An event the browser built from real input always lists itself.
Nearby checks in Input & behaviour
- An upper-case letter was typed with Shift or Caps Lock
shift-less-capitalsOn a physical keyboard, a capital letter is the letter key pressed with Shift held or Caps Lock on: the key event for 'H' arrives with code… - A mouse press landed inside the viewport it was delivered to
press-inside-viewportA physical mouse press lands wherever the pointer is. If the pointer is outside the page's viewport, the press goes to the browser's own… - 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 velocity and acceleration vary physically
pointer-kinematicsVelocity, acceleration reversals, direction changes, and timestamp quantisation catch constant-speed curved automation missed by linearity. - Pointer events arrive on hardware time
pointer-event-cadenceWhere the linearity check reads the path's shape, this one reads its clock.
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 rawupdate-carries-its-sample belongs to.