Screen Region Coverage Tester
Mark regions receiving touch input.
Tap, click or press Space to keep count.
Tap anywhere inside or press Space
How the Screen Region Coverage Tester Works
The Screen Region Coverage Tester splits the screen into a grid of cells and marks each cell green once a touch reaches it. Cells that stay gray after you drag across the whole screen point to dead zones in the touch panel.
- Open the test grid: The screen fills with a grid of gray cells, such as 10 × 20.
- Drag across every cell: Slide a finger row by row until you cover the full screen.
- Watch cells turn green: Each touched cell changes color and stays marked.
- Find gray cells: Retry any gray cell. Cells that stay gray after 3 tries mark a dead zone.
Screen Region Coverage Tester Formula
The Screen Region Coverage Tester coverage equals marked cells divided by total cells, multiplied by 100.
- Marked cells
- Cells touched at least once
- Rows × Columns
- Total cells in the grid
Example: A 10 × 20 grid has 200 cells. After a full pass, 197 cells are marked. Coverage = 197 ÷ 200 × 100 = 98.5%. Three cells need a retest.
Screen Region Coverage Tester Reference Table
The Screen Region Coverage Tester conversion table shows cell size on a 6.1-inch phone (390 × 844 CSS px) for each grid density.
| Grid | Total cells | Cell size (px) | Cell size (mm) | Detail level |
|---|---|---|---|---|
| 5 × 10 | 50 | 78 × 84 | 20.6 × 22.3 | Quick check |
| 8 × 16 | 128 | 49 × 53 | 12.9 × 14.0 | Standard test |
| 10 × 20 | 200 | 39 × 42 | 10.3 × 11.2 | Detailed test |
| 15 × 30 | 450 | 26 × 28 | 6.9 × 7.4 | Fine test |
| 20 × 40 | 800 | 20 × 21 | 5.2 × 5.6 | Repair-grade test |
About the Screen Region Coverage Tester
A Screen Region Coverage Tester is a diagnostic grid that checks whether every part of a touchscreen responds to touch. The test finds dead zones, dead strips and weak edges.
Dead zones come from a cracked digitizer, a damaged flex cable or a poorly fitted replacement screen. Repair shops run a grid test like this one before and after each screen replacement.
Ways to Use the Screen Region Coverage Tester
There are 5 main uses of the Screen Region Coverage Tester, including repair checks and used-phone inspection.
- Repair checks: Technicians confirm a new screen responds in every cell.
- Used-phone inspection: Buyers test a second-hand phone for dead zones.
- Screen protector checks: Users test edges after fitting a curved protector.
- Kiosk maintenance: Staff test public touch screens for worn areas.
- Warranty evidence: Owners screenshot the grid to show a dead zone to support teams.
Tool Details
- Category
- Touch & Gesture Diagnostics
- Controls
- Taps and keys
- Input Support
- Touch, Pen, Mouse, Keys
- Offline Ready
- On your device