How to find touch screen dead zones
Test your phone, tablet or laptop touch screen in the browser with five tests. Draw with several fingers to see how many touch points your screen tracks and how big each contact is. Sweep the dead-zone grid to find areas that don't respond, edges included. Run a timed ghost-touch watch that logs phantom taps with their position. Tap targets to check accuracy and calibration offset, and measure how many touch samples per second your browser receives. Fullscreen works on iPhone too.
A dead zone is an area of the digitizer that doesn't register touches, often along a crack, an edge or where a screen protector lifts. Go fullscreen in Dead zones mode and swipe slowly over every cell. Healthy cells turn green; cells that stay red after you've touched them several times are dead. Edge cells are tinted amber because corners and curved edges fail first. Use the Fine grid to pin down small dead spots.


