Touch Screen Test
Swipe across the grid to reveal dead zones and count your screen’s touch points.
Drag your finger (or several) slowly across the whole grid until every cell fills. Cells that never fill mark dead digitizer zones.
How it works
The grid divides your screen into cells that fill cyan the moment they register touch. Sweep your finger slowly across the entire surface — edges and corners included, since digitizer failures cluster there. Any cell that stays dark after several passes marks a dead zone where the touch layer no longer responds. The counter tracks your completion percentage, and the fullscreen button extends the grid over the whole display so the browser chrome doesn't hide a faulty strip.
The touch points readout shows how many fingers your screen tracks simultaneously — place them all down at once to find your maximum. Most phones track 10; budget tablets often 5. Before condemning a screen, restart the device (touch controller glitches often clear) and retest; consistent dead zones across restarts and browsers indicate hardware failure. On a laptop, make sure you're touching the screen — a trackpad reports only one pointer, which is why it shows "1". Suspect the display panel itself rather than touch? Run the dead pixel test too.
Finding dead zones and touch points
Drag your finger across the grid to paint every cell; any cell you cannot fill after several passes marks a spot where the digitizer isn't registering touch. Place several fingers at once to read your screen's maximum simultaneous touch points. It works in any phone or tablet browser and reveals faults that are invisible until you hit exactly the wrong spot.
Reading the results
| Result | Meaning |
|---|---|
| A region never fills | Likely dead digitizer zone — restart first, then re-test |
| Max touch points = 10 | Full multi-touch (most modern phones) |
| Max touch points = 5 | Common on budget tablets — normal for the hardware |
| Max touch points = 1 on a laptop | The trackpad is being read, not a touch screen |
Before you call a zone dead
- Remove any screen protector — a lifted or thick protector kills touch sensitivity in patches.
- Clean and dry the screen; moisture and grease cause phantom or missed touches.
- Restart the device — a glitched touch controller often clears on reboot.
- Re-test in a different browser to rule out a software issue before concluding it's hardware.
A stylus (active or passive) also registers as touch, so you can verify pen coverage across the whole panel the same way.
Ghost touch: when the screen presses itself
The opposite fault — cells filling without your finger — is ghost touch, and its causes rank differently from dead zones. A cheap or uncertified charger injecting electrical noise is the number-one trigger: if ghost touches happen mainly while charging, swap the charger before blaming the screen. After that come a damaged or moisture-contaminated screen protector, extreme heat, and — after a drop — a loose digitizer connector. Software can also misfire after an OS update; test in safe mode (Android) or after a restart (iPhone) to rule that out. Persistent ghost touch in the same spot with no charger attached usually means the digitizer layer is failing and the panel needs service.
Edge and corner accuracy
Digitizer faults rarely start in the middle of the screen — they creep in from the edges, where the sensor grid terminates and drop damage concentrates. Trace slowly along all four borders and into each corner: skipped cells only at one edge, with the centre painting fine, are the classic early signature of a failing digitizer or a delaminating panel. Catching it early matters if the device is still under warranty — an edge dead zone documented now is a free repair; six months later it's often a spreading fault and an argument.
Troubleshooting
› Some grid cells won’t fill no matter what
If a region never responds across multiple swipes, that zone of the digitizer is likely dead. Try a restart first — some touch controller glitches clear — then test in a different browser to confirm.
› Max touch points shows 1 on my laptop
That usually means the trackpad, not a touch screen, is being detected — trackpads report a single pointer. If your laptop has a real touch display, touch the screen itself, not the trackpad.
Frequently asked questions
› How do I find dead zones?
Drag your finger slowly across the whole grid. Cells fill as they register touch — any cell you cannot fill after several passes marks a dead digitizer zone.
› What are multi-touch points?
The number of simultaneous fingers your screen tracks. Most phones support 10; budget tablets sometimes 5. Place multiple fingers at once to see your maximum.
› Does this work with a stylus?
Yes — active and passive styluses register as touch input, so you can verify pen coverage across the display too.