Dead Zones
Touchscreen diagnostics use browser pointer events locally for finger, stylus, and panel checks.
Touchscreen Dead Zone Test: Grid Sweep, Missed Cells, Unresponsive Areas, And Touch Coverage Map
Drag across a touch map to find missed cells, dead touch zones, and tracking gaps.
What this test checks
- Touch point detection
- Coordinate accuracy and tracking gaps
- Stylus or finger input behavior
- Check Coverage Percentage And Blank Regions
How to read the result
Dead Zones is most useful when you test the center, corners, and edges. Repeated misses in the same area matter more than a single bad tap, especially on phones, tablets, and touch laptops.
Use Fullscreen For Edge-To-Edge Coverage
A dead zone test is most useful when the grid reaches the actual screen edges. Fullscreen mode reduces browser chrome and helps users inspect the corners, bezels, and center area properly.
Drag Slowly Through Every Cell
Move a finger or stylus across the grid in straight passes. Cells that turn active were detected; cells that remain untouched after repeated passes may point to a dead touch zone or calibration gap.
Check Coverage Percentage And Blank Regions
The coverage value summarizes how much of the grid has registered input. A cluster of blank cells is more meaningful than one missed cell because it may reveal panel damage or a driver issue.
Retest After Cleaning The Glass
Screen protectors, moisture, dirt, and palm rejection can affect touch input. Cleaning the panel and rerunning the sweep helps separate temporary interference from a true dead zone.
Related I/O Checkup Tools
What does Dead Zones measure?
Drag across a touch map to find missed cells, dead touch zones, and tracking gaps.
Do I need to install anything for Dead Zones?
No. Dead Zones runs directly in a modern browser. Some checks may ask for permission when they need camera, microphone, gamepad, pointer lock, touch, or audio output access.
Are results uploaded?
The test runs in your browser and uses local input events or browser hardware APIs for the visible diagnostics.
Why should I run related tests too?
Related tools help separate hardware issues from browser timing, display behavior, input device settings, or permission problems, which makes the final diagnosis more useful.
Detailed Testing Guide
Touch symptom
This touch page checks how the screen receives finger, stylus, or pointer contact in real browser events.
Start with a baseline run before changing device settings. Record any repeated symptom so the next comparison is useful.
Touch evidence
Watch contact location, missed areas, edge behavior, multi-touch count, line continuity, and pressure when supported.
Watch Touch point detection, Coordinate accuracy and tracking gaps, Stylus or finger input behavior, Check Coverage Percentage And Blank Regions. These observations come from the browser; they do not reveal hidden firmware or factory calibration data.
Surface test method
Clean the glass, test the center first, then repeat suspicious corners, edges, or cells slowly.
Keep the test conditions stable. Changing browser, cable, port, lighting, surface, volume, grip, or selected device all at once makes the result harder to trust.
Result reading
Screen protectors, water, cases, palm rejection, and operating-system gestures can change the result.
A repeated pattern matters more than a single spike. When something looks wrong, confirm it with another pass and compare a related tool before deciding the device itself is defective.
Limits and next checks
Use touch point, multi-touch, dead zone, tap accuracy, drawing, edge, and event log pages as a sequence.
For a closer comparison, try Touchscreen Test, Multi-Touch Test, Tap Accuracy Test, Touch Dead Zone Test. Keep the same device and connection while you investigate the next symptom.