What the Mouse Drag Test Measures
Drag-and-drop requires the browser to keep receiving a held button state while the pointer moves. This tester watches the selected button bit, pointer movement and capture lifecycle.
A completed run requires at least three seconds of hold, 250 CSS pixels of movement and reaching the finish target before release.
How to Use the Mouse Drag Test
- 1Select left, right or middle button.
- 2Press and hold inside the start target.
- 3Move while continuing to hold for at least three seconds and 250 CSS pixels.
- 4Reach the finish target and release only when it becomes ready.
- 5Repeat several runs and compare any early releases.
How to Interpret the Result
A repeatable early release may be consistent with a switch, connection or software problem. One failed run can be caused by finger movement, focus loss or browser pointer cancellation.
Lost capture is useful context, not proof of a hardware fault. For unwanted duplicate presses, use the Double Click Test.
Distinguishing Release, Cancellation and Lost Capture
An Early Release means the selected button state ended before the hold time, travel distance and finish conditions were all met. Pointer Canceled means the browser canceled the pointer sequence. Lost Capture means the browser stopped routing that pointer's events to the test surface. These labels describe distinct event paths and should not be merged into one hardware verdict.
Repeat a run with the same button and motion before comparing counts. A consistent release during an ordinary file drag or text selection can be investigated further, while a single canceled run may come from a gesture, focus change or browser behavior. The test area uses pointer capture to keep observing a drag that leaves its visible target.
Browser Limitations
The browser cannot inspect electrical switch contacts or distinguish every hardware, firmware and software cause. Pointer cancellation can be caused by gestures or focus changes. Right-button behavior also varies by browser.