Device tests · Input Devices
Touch Screen Test
Map the touch events your phone, tablet or touch-enabled laptop delivers to this browser. Drag a finger through the coverage grid, compare simultaneous contacts and optionally watch for unexpected touches while the device rests.
The test records contacts, not the condition of the digitizer. An area not reached during a run needs a deliberate retest; it is not automatically a dead zone. Mouse input never fills the touch grid.
- Local observations
- No hardware certification
Only touch contacts mark coverage. Mouse and stylus input do not fill the grid.
Local touch observations
- Coverage
- 0.0%
- Cells touched
- 0 / 216
- Active contacts
- 0
- Maximum contacts
- 0
Touch-start observations: 0 · Browser maxTouchPoints: Not read yet
Your result
What your result means
Coverage is the proportion of 216 grid cells that received an in-area touch event. A checkmark means the browser reported a touch position inside that cell, not that every physical point inside it was tested. Unmarked cells mean only that no matching event reached this page during your run.
Maximum contacts is the greatest number of active touch pointer IDs observed together. It is a lower-bound observation for your attempt, not a certification of the controller’s full multi-touch capability. Browser maxTouchPoints is a capability report and can differ from the number you actually demonstrate.
Ghost Touch Watch waits three seconds and then counts touch-down events in the area for ten seconds. A reported event could come from an unintended real contact, interference or a device/input issue. No event is not proof that an intermittent problem never occurs.
Procedure
How the test works
- 01
Prepare the device
Use a stable surface and disconnect unnecessary accessories if safe. Clean and dry the screen following its maker’s instructions; remove gloves unless supported by the touchscreen.
- 02
Start coverage
Press Start Touch Coverage and slowly trace across rows, columns and edges. Only touch input marks cells. Avoid using a mouse as a substitute for a finger.
- 03
Compare multiple fingers
Place several fingers separately inside the area and compare active and maximum contacts. Keep fingers sufficiently apart; the controller may merge nearby contact shapes.
- 04
Retest gaps
Finish the run, then select Retest missed areas. Previous coverage remains so you can deliberately cross remaining cells rather than interpreting a fast missed pass as damage.
- 05
Watch without contact
Select Ghost Touch Watch, place the device down during the countdown and leave the area untouched. Touch events are counted only during the ten-second observation.
- 06
Exit freely
Finish / Stop remains above the grid, outside its drag surface. Exit fullscreen or Escape restores ordinary browsing. Reset removes the local run.
Methodology
How Testpartout measures this
This implementation uses browser observations and local calculations, with no hardware certification.
What the implementation does
- The grid has 12 columns and 18 rows; client coordinates are normalized against the current test area before assigning a cell.
- Pointer events with pointerType touch mark cells. Mouse is excluded and stylus input is noted separately. Captured touch pointers allow a drag to continue until release.
- Pointer-up and cancellation remove active contacts. Focus or visibility changes clear contacts; a hidden page cancels an active observation.
- No interpolation fills cells between event samples. Fast movement may skip cells, which is why slow deliberate coverage and retesting matter.
- Fullscreen is requested only from a control. If unavailable, only the browser area is covered.
Limits of a browser measurement
- The page cannot inspect the digitizer electronics, force operating-system edge gestures to reach it or certify the whole panel.
- A screen protector, moisture, gloves, contact size and gesture speed can affect observations. Browser event sampling may omit positions along an otherwise working path.
- Unexpected events do not establish a repair diagnosis. A short watch can miss intermittent symptoms.
Privacy
What happens to your data
This section describes the behaviour of the code on this page, not an intention.
- Diagnostic events, coordinates, timings and observations stay in current page memory. They are not uploaded or saved as raw diagnostic data.
- No camera, microphone, account or server storage is used by this test.
- Only start and complete lifecycle events may be sent after analytics consent; no result values are included.
Troubleshooting
If the test does not behave as expected
Missed taps and broken drag paths
Repeat slowly in the same region, then compare an operating-system app. If a drag breaks consistently across several apps, a device-side issue becomes more plausible, but this page cannot identify its source.
Edge gestures
System navigation gestures may intercept contacts near edges. Fullscreen reduces browser chrome but does not disable operating-system gestures or grant access beyond the page.
Moisture and protectors
Water, grease, damaged protectors or trapped contamination may affect capacitive sensing. Power off before cleaning when recommended; use manufacturer-approved methods and never solvents or pressure not recommended by the maker.
Factors
Interpret observations in context
Charger or interference
Symptoms that appear only while charging are worth comparing with a supported known-good charger and safe outlet setup. Electrical interference is one possibility, not a conclusion from a browser event. Stop using damaged accessories.
Capacitive sensing
Many touchscreens detect changes in an electric field caused by a finger. They do not measure mechanical pressure like a button. Gloves, very dry contacts or unusually close fingers can change how a controller interprets input.
No touch events
Check that the device actually supports touch and that you are using a finger in the active area. A zero maxTouchPoints report or no events in one browser is not enough to identify a hardware fault.
FAQ
Frequently asked questions
- Can mouse movement complete the touchscreen test?
- No. Only pointer events identified as touch mark coverage cells. Pen input is displayed separately and mouse input is excluded.
- Does an unmarked cell prove a dead zone?
- No. It means no touch position was observed in that cell during the run. Slowly cross it again and compare another app before suspecting hardware.
- What does Ghost Touch Watch detect?
- It counts touch-down events reported inside the area during a ten-second watch after a three-second countdown. An event is an observation, not proof of ghost touch.
- Can this test repair the touchscreen?
- No. It is an observation tool. Use safe cleaning, supported OS checks and manufacturer support rather than destructive repair attempts.
- Why is maximum touch count lower than maxTouchPoints?
- The property is a browser capability report. Your observed count depends on the contacts you made, spacing, OS gestures and events delivered to the page.
- Are my touch coordinates uploaded?
- No. Coverage and rough unexpected-event positions remain only in this page’s memory and are not sent to analytics or saved.
Found an issue with this test? Report it.