Touch Screen Test: Dead Spots & Multi-Touch

How to test a touch screen

Press Full screen, then drag one finger slowly over the whole grid. Every square you touch turns green. Go over the edges and corners too, where dead spots are most common. A square that will not turn green after a few tries marks a dead zone. Then put two, three or more fingers down together and read Most at once to check multi-touch.

Dead zones and ghost touches

A dead zone is a strip or patch that ignores your finger, often after a drop or a screen replacement. Ghost touches are the opposite: taps you did not make, which show up here as rings appearing on their own or squares turning green while you hold the phone still. Remove the screen protector and case first, since a bubble or a tight case edge causes both. Clean and dry the screen, and unplug a cheap charger, which can create electrical noise that triggers ghost touches.

How many touch points should it have?

Most phones and tablets detect 5 or 10 fingers at once, and Windows touch laptops usually 10. Device supports shows what the browser reports; Most at once shows what you reached. If you cannot get past one or two fingers, the touch layer may be damaged, or you are using a touchpad, which this page sees as a mouse.

Touch works here but not in an app

Then the screen is fine and the app is at fault: update or reinstall it, or clear its cache. If the whole phone ignores touches at random, restart it; on Android, booting into safe mode shows whether a downloaded app is to blame.

Laptop touch screen not working

On Windows, open Device Manager → Human Interface Devices and check that HID-compliant touch screen is enabled; disabling and enabling it again often brings a dead screen back. Pen and touch settings also have a switch to turn touch off. Run Windows Update for the display and touch drivers.