Drag your finger across the grid to light up squares. If certain squares never activate, that may indicate a dead zone.
Use multiple fingers to test multi‑touch capacity (many devices support 5–10 touch points).
Common issues
Screen protector interfering with touch
Moisture / wet hands
Digitizer damage after a drop
Battery swelling pushing the panel
Tips
Remove gloves; use bare fingers
Restart the device and try again
Test in landscape and portrait
Try another browser if needed
Privacy: this test runs locally in your browser and does not upload your touch data.