Touch Screen Test
Fullscreen fingertip grid: swipe to check, tap to flag dead zones.
Enter fullscreen and swipe every cell. Green means that cell responds to your finger; if a cell feels dead, skip-drift or unresponsive, tap it to mark it red.
A browser can detect where your finger lands, so every cell you swipe turns green — but it cannot tell by itself whether a cell is faulty. Dead / drifting / unresponsive zones are therefore judged by you: tap that cell to mark it red.
Why choose this touchscreen test?
Adaptive grid
The grid recalculates to keep every cell about a fingertip in size on any screen — phone, tablet, any orientation.
Swipe to check, tap to flag
Dragging a finger across a cell turns it green (the touch engine registered it); tap a dead, drifting or unresponsive cell to mark it red.
End anytime with a long-press
No extra buttons on screen — just the grid. Long-press any cell to finish the test and return to the touch test page.
How to test
- 01 · Start the test
Tap Start to enter fullscreen (a full-viewport overlay on devices that block fullscreen).
- 02 · Swipe every cell
Drag your finger across the whole grid so every cell turns green.
- 03 · Mark faults & finish
Tap any cell that feels dead / drifting / unresponsive to flag it red; long-press any cell to end the test and return to the touch test page.
Frequently asked questions
Can the page really detect a broken touch zone?
No strictly automatic detection exists — a browser only reports where your finger landed. This is why failing zones are marked by you. That manual judgement is the practical, honest way to map a faulty digitizer.
Why do cells turn green when I swipe?
Pointer events register every cell under your finger while dragging. A cell that never turns green while you swipe across it is exactly where to look for a dead zone.
What causes dead / floating touch zones?
Broken/aged digitizer film, cracked glass, water damage, battery swelling or a loose touch connector. A red cluster usually means hardware attention.
How many cells should I expect?
It adapts to your screen — roughly one cell per fingertip, so phones get ~8 columns and tablets get more, never too tight to test.
The technical principle behind the test
What green means
A green cell just means the browser received your touch there — that zone of the digitizer responds.
Why red is manual
A browser can only detect where you touched. It cannot know a zone “fails” — only your feel of dead/patchy response can. So you mark it red.
What the result tells you
Green coverage proves the touch engine works across the screen; any red zone points to an area worth a hardware check or repair.
What causes faulty touch zones
Hardware causes
- Cracked or delaminated digitizer film.
- Water / moisture damage to the touch matrix.
- Battery swelling pressing the panel, or a loose flex connector.
Software first
- Restart and update the OS / display driver first.
- Remove thick or incompatible screen protectors.
- If a red zone persists across restarts, hardware is the likely cause.