A move only reports a button down after that button was pressed
Moves that report a held button follow a press of that button in the document. Information only, because drags entering from outside the page do the same (severity: info).
What a detector infers
MouseEvent.buttons on a move reports which buttons are held, and a button can only be held after it has been pressed. For a page that has watched the pointer since it loaded, a move reporting a button down with no matching press in the document is unusual.
A DevTools-protocol client produces it directly: Input.dispatchMouseEvent accepts a buttons bitfield on mouseMoved and Chrome passes it through, so a client that sets it on moves produces held-button moves with no press before them. Measured: a raw mouseMoved carrying buttons 1, with no press, delivered a pointermove reporting buttons 1. It is the mirror of pointer-buttons-during-drag, which fails a drag whose moves report nothing held.
This one is information only, because there are ordinary ways to arrive with a button already down: a drag that started outside the page — in another window or on the browser's own interface — and enters the document held, or a remote-desktop client relaying button state. Only the failing side has been measured.
How to resolve it
Set buttons on a move only between the matching press and release. A held-button move with no press before it describes a drag that never started.
Nearby checks in Input & behaviour
- Every raw pointer update carries at least its own sample
rawupdate-carries-its-samplepointerrawupdate fires for each pointer report as it arrives, without waiting for the next frame, and Chrome builds each one from a real… - 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… - 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 buttons-without-press belongs to.