Touch Screen Test Online: Find Dead Zones & Ghost Touch

How to use it

Choose Full grid and tap Start grid test — the test surface goes full screen.

Swipe slowly over the whole screen until the squares turn green, then tap Done.

Touch the blinking squares again; if they stay red, you have found a dead zone.

Use Lines & drawing to spot breaks and jitter, and Multi-touch to count fingers.

For touches that happen by themselves, run Ghost touch and keep your hands off until the countdown ends.

Features

Full-screen grid test with a progress percentage and blinking unresponsive squares

Three square sizes: fine for small dead spots, large for a quick check

Free drawing with pressure (when the screen reports it) and automatic marking of line breaks and jumps

Horizontal, vertical and diagonal guides plus line jitter measured in pixels

A coloured circle per finger and the most simultaneous touches next to the device's reported limit

Ghost touch detection over 10, 30 or 60 seconds with the time and position of each touch

Live touch sampling rate and event delay while your finger moves

Full screen on iPhone too; nothing to install and no data sent anywhere

What this test checks#

The touch layer (digitizer) is a transparent sheet on top of the display that senses your finger. When part of it is damaged, that area stops responding (a dead zone), lines break halfway, or the phone starts registering touches on its own. This page has four tests: a full-screen grid for dead zones, lines and drawing for breaks and jitter, multi-touch to count fingers, and ghost touch for touches that happen by themselves. Everything runs in your browser, so it works as a Samsung, Xiaomi or iPhone touch screen test without installing an app.

How to read the results#

Grid: if a square stays red after several swipes, and it is always the same square, that spot is a dead zone. A single square in a rounded corner or under the camera cutout is usually not a fault.
Lines: a line that breaks halfway or gets a red "jump" circle means the panel lost your finger for a moment. If it always happens along the same horizontal or vertical band, the touch layer or its connector is probably damaged.
Multi-touch: most phones track 5 to 10 touches at once. A number far below the reported limit, or circles that jump around, point to a touch problem.
Samples per second: the number you see while moving a finger is how many touch reports reach the browser each second. It also depends on the screen refresh rate and the browser, so compare phones in the same browser.

What causes ghost touch?#

Ghost touch means the phone registers touches you did not make: apps open, text gets typed or the page scrolls by itself. The usual causes:

A poor charger or cable: electrical noise confuses the touch layer. If ghost touches only appear while charging, replace the charger.
Screen protector: a cracked or bubbled protector, or one with raised edges, presses on the edges of the screen. Test once without it.
Moisture and grease: water drops, sweat or wet fingers create false touches. Wipe the screen with a dry cloth.
Heat and cases: a tight or metal case and high temperatures can also cause false touches.

When is it a hardware fault?#

If the same dead zone or ghost touch comes back after a restart, after removing the protector and case, without the charger and even in Safe Mode, software is not the cause. Drops, pressure on the screen, earlier repairs and non-original replacement screens are common reasons. The fix is a new touch panel, and on most modern phones the touch panel and display are one part that is replaced together.

Tips#

On many Samsung models the code *#0*# opens a hardware test menu, and on Xiaomi *#*#6484#*#* opens the CIT menu. iPhone has no touch test menu, so open this page in Safari.
Turn the brightness up and clean the screen before testing so the squares are easy to see.
If the phone is slow or freezes when you touch it, the screen is not always to blame; run this test first to tell a touch panel fault from a software problem.

Frequently asked questions

Can a touch screen dead zone be fixed with software?

If the dead zone survives a restart, removing the screen protector and a system update, it is a hardware fault and no app will fix it. The only fix is replacing the touch panel or display.

Does this touch screen test work on iPhone?

Yes. iPhone has no hidden touch test menu, but this page works in Safari. Because Safari on iPhone does not give web pages true full screen, the tool stretches the test surface over the whole visible screen instead.

Why does my touch screen act up only while charging?

A poor charger or cable adds electrical noise that the touch layer reads as touches. Run the ghost touch test with and without the charger; if the results differ, replace the charger.

What is a normal samples-per-second number?

Most phones show roughly 60 to 240, and gaming phones can go higher. The browser and the refresh rate affect it, so use it for a rough comparison, not as the factory spec.