Repeat slowly in the same stage, then try a direct USB connection or charged wireless mouse. The page cannot know when your finger lifted.
Part of the Mouse test. Run the full mouse test first for a complete device check.
Release appears while holding Run was interrupted No movement appears
Mouse drag test
Record press, movement, release and cancellation events during a sustained left-button drag.
Also known as: mouse drag test. Free, online, and no download required.
No permission neededNothing uploaded
Hold the left mouse button in the stage and move before releasing.
01
What the mouse drag test checks
| Check | How it is measured | Fails when |
|---|---|---|
| Press and release | The browser's pointerdown and pointerup events for the left button. | A hold ends before you expected, or no release reaches the focused page. |
| Movement | Distance from the starting pointer coordinate in CSS pixels. | Movement stops arriving while the pointer remains inside the stage. |
| Cancellation | Pointer cancellation or loss of window focus. | The run is interrupted before a normal release can be observed. |
How to run the mouse drag test
- Press and hold the left button inside the stage.
- Move within the stage while holding and watch the distance.
- Release, note the recorded interval, and repeat under the same connection.
- Compare another button or mouse if the same symptom recurs.
If something failed
Keep the window focused and the pointer inside the test area. Cancellation is separate from a button release.
Begin inside the stage and keep the pointer in this browser window. Compare the general mouse test if the pointer itself stops moving.
02
How to read the result
How to read the event log
The log marks the first left-button press, any release, and cancellation. Distance is the straight-line displacement from the starting coordinate, not a measurement of physical mouse travel. A normal release at the end of your intended drag is expected.
If you repeatedly see a release before you consciously let go, repeat with another connection and mouse. This comparison is stronger than a single log entry because the page cannot independently observe your finger.
Measurement limits
The browser sees pointer events after the operating system and drivers have handled them. Window blur, pointer cancellation, navigation, and leaving the browser can interrupt the run. The page cannot read switch contacts, sensor firmware, or events delivered only to another application.
A clean run only confirms that events arrived during that attempt. For intermittent behavior, capture several runs and compare the same drag in the application where the problem originally occurred.
03
Mouse drag test questions
Does a recorded release prove the button failed?
No. The page cannot tell whether your finger lifted. Compare repeatable releases under controlled conditions with another mouse or computer.
Why was my run cancelled?
The window lost focus or the pointer stream was cancelled. Keep the pointer in the area and try again before interpreting the attempt.