Mouse Drag Test
Hold and drag to catch your mouse button releasing mid-stroke. Switch to Angle Snapping mode and draw the guide to see if the sensor flattens your diagonal.
How to use
- Hold and drag. Press and hold your left button, then drag across the surface in any direction. Change direction a few times and keep the button held for at least 30 seconds.
- Watch the dropout counter. Each time the button releases and bounces back within 80 ms, the counter ticks up and a red dot marks the location. Zero is the target. Any count above zero points to a failing switch.
- Run it longer for intermittent faults. A degraded switch may hold fine for 20 drags and then drop once. If you suspect a fault, run the test for at least a minute before trusting a zero.
- Check angle snapping. Press Reset, switch to Angle Snapping, then slowly draw along the diagonal guide from left to right. Green means your line held the guide's angle. Red means it came out much flatter, which is what angle snapping does to a diagonal.
Why test this
Left button dropping mid-drag is the kind of fault you dismiss the first time. Your selection fails halfway through, your file lands in the wrong folder, your spray breaks mid-hold. You assume you slipped. A week later it happens again. The switch is the culprit. Mechanical contacts wear with use. A worn switch can open for an instant while you hold it, and the computer reads that as a real release, so the drag breaks. The fault comes and goes, so it can pass a few normal clicks and still show up once you hold the button down for a minute. The counter records how often it happened, and the red dots mark where on the surface. Switch to Angle Snapping mode for a second check: draw the diagonal guide and see whether the sensor tracked your hand or quietly straightened the line.
What the results mean
The dropout counter adds one each time the button goes down again less than 80 ms after a release, moving or not. Zero is healthy. If you held the button down the whole time, a dropout points to the switch, so the verdict flags even one. Red dots on the canvas mark where each new press landed. In Angle Snapping mode, the result comes from the slope of your drawn line. Drag the guide from left to right at a steady pace, then release. Green means your path held the guide's angle: the sensor tracked your hand without correcting it. Red means your line came out much flatter than the guide, which is what angle snapping does to a diagonal. Draw at a slow, steady speed and cover at least half the guide, or the test asks you to draw more.
FAQ
- What is a mouse button dropout?
- A dropout happens when your left button releases briefly while you're still holding it. The switch contacts bounce open, the OS registers a momentary release, then the button closes again. In-game that breaks a spray, a hold-to-fire, or a drag-select without you lifting a finger.
- Why does my mouse keep letting go mid-drag?
- A worn switch. Its contacts can bounce open while you hold the button, and the computer takes that as a release and a new press, so the drag ends. Because it's intermittent, a long hold catches it more often than a few quick clicks.
- What does the 80 ms threshold mean?
- If the button goes down again less than 80 ms after a release, the test counts a dropout. That's the pattern a worn switch leaves when its contacts bounce open mid-hold. A fast click on purpose can land under 80 ms too, so press once and keep holding.
- What is angle snapping?
- Angle snapping is firmware-level correction in some mouse sensors. When you move the mouse, the sensor nudges your path toward the nearest horizontal or vertical line. That works fine for spreadsheet work, but removes the micro-adjustments you need to track a moving target in a game.
- How do I turn off angle snapping?
- Only some mice let you change it. SteelSeries GG has an Angle Snapping setting for several of its mice; on other brands, look in your mouse software for Angle Snapping or Angle Correction. Toggle it off, then run the test again to confirm. If the app has no such setting, the sensor firmware decides, and this test shows you what it does.
- Can I fix a switch that is dropping out?
- A shot of contact cleaner into the switch gap can extend its life by weeks. Desoldering the switch and fitting a new one is the permanent fix. If the mouse is still under warranty, contact the manufacturer before opening the case.
How we measure
Button Dropout reads Pointer Events on the canvas. A hold runs from the press (pointerdown) to the release (pointerup), and Hold time adds up all your holds.
A press that comes less than 80 ms after the last release counts as a dropout, whether the pointer moved or not, and a red dot marks where it landed. One dropout is enough for the fault verdict. The first press after a Reset never counts.
Angle Snapping draws a guide that starts 20 px inside the left edge, ends 20 px inside the right edge and rises 80 px. On a narrow screen the same rise covers less width, so the guide is steeper.
Your stroke is every pointer position from press to release. It needs at least 10 readings and has to travel at least 50% of the guide from left to right, or the verdict asks you to draw more.
The test fits a straight line through your stroke by least squares. If that line's slope is under 25% of the guide's slope, the verdict reads Angle snapping detected. Anything steeper reads Not detected.
Share sends a link with your dropout count and hold time. Angle Snapping results stay on your screen.
What a browser cannot see
Pointer Events report a press only when the first button goes down. With two buttons down, a bounce of one never reaches the test, and neither does a press of the second. Hold one button only. Any button, a finger or a pen starts a hold.
A quick press on purpose under 80 ms after a release counts too, so keep the button down instead of clicking. The 80 ms line is our call.
The test sees only the presses your mouse reports. A bounce the mouse filters out before it reports one never shows up here.
The stroke is the cursor path after your system has moved it, and the browser merges several moves into one event, often once per frame. Draw slowly so the stroke collects enough readings.
How close to horizontal a line must be before a sensor snaps it differs from sensor to sensor and is rarely published. Not detected holds for this guide's angle only.
The test only compares your line with the guide. It can't tell a flat hand from a sensor that flattens, so draw a few strokes.
Every release-to-press gap is timed on two clocks: the browser's time stamps on the two events, and the moments the page handles them. If they disagree by more than 25 ms, the page was busy and the stamps win. Drag in Firefox on Windows and the stamps move in steps of about 15.6 ms. A gap caught while the page was busy can then be up to 16 ms off.
Sources
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