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Touch Screen Test

Find dead zones on a phone or tablet touch screen and check how many fingers it detects at once with a full-screen multitouch test.

Runs in your browser. Nothing is uploaded.

Test every part of your touch screen

The test fills your screen with a grid. Slide your finger over every cell until the whole screen is green, then place several fingers at once to check multitouch.

Before you start

  • Remove any gloves and clean the screen.
  • Slide slowly near the edges and corners: that is where dead zones usually are.
  • The controls move to the other edge when your finger comes close, so you can reach every cell.

Results

Screen coverage

Not tested

Start the test and slide over the whole screen.

Cells not touched

Not tested

Start the test and slide over the whole screen.

Most fingers at once

Not tested

Start the test and slide over the whole screen.

Your previous runs

Saved only in this browser.

No previous runs yet.

    What this touch screen test checks

    A touch screen is covered by a fine mesh of sensors, called the digitizer. When part of it fails, taps and swipes stop working in one area of the screen, while the rest behaves normally. These areas are called dead zones, and they are easy to miss in everyday use.

    This test covers your whole screen with a grid of cells. Each cell turns green when a finger passes over it, so any zone that never reacts stands out immediately. The test also shows every finger touching the screen with its own number, which lets you check multitouch: how many fingers the screen can follow at the same time.

    Everything happens in your browser. Nothing you touch is recorded or sent anywhere.

    How to test your touch screen

    1. Clean the screen and remove gloves or a very thick screen protector if you can.
    2. Press Start the touch test. The grid fills the screen. On phones and tablets that support it, the page switches to full screen.
    3. Slide one finger slowly over every row, including the edges and corners, until the whole grid is green. Dead zones are most common near the edges, around cracks and where a phone has been bent.
    4. Place several fingers at once and move them. Each finger gets a numbered circle. The top bar shows how many fingers are detected now and the maximum so far.
    5. Press Finish in the control bar. The bar moves to the other edge when your finger comes close, so every cell stays reachable. On a computer, you can also press Escape.
    6. Read your results below the test and save them if you want to compare with another device or share them.

    How to read your results

    Screen coverage and cells not touched

    A result of 100% means every zone of the screen responded. If a few cells stayed red, go back and slide over them slowly several times. A cell that turns green on a second pass was simply missed. A cell, a line or a whole block that never turns green points to a dead zone in the digitizer.

    The map shows exactly where the untouched cells are. A straight line of red cells often matches a damaged sensor line; a patch of red cells around a crack usually follows the physical damage.

    Most fingers at once

    Most phones and tablets follow 5 to 10 fingers at the same time. The number your device reports is shown next to your result. If you reached fewer fingers than that, try again with your fingers spread apart: fingers too close together can be read as one. A screen that loses fingers that are well apart, or that confuses them, may have a digitizer problem.

    Troubleshooting

    The screen reacts where I did not touch it

    Random touches, often called ghost touches, are usually caused by moisture, a charger with electrical noise or a damaged digitizer. Dry the screen, unplug the charger and try again. If ghost touches continue, the screen may need repair.

    A zone never turns green

    Remove the screen protector and try again: bubbles or a thick protector can block touches near the edges. Restart the device to rule out a software freeze. If the zone still does not respond, the digitizer is likely damaged in that area.

    The page scrolls or zooms instead of painting cells

    This should not happen inside the test. If it does, make sure you started the test with the button, then reload the page and try again. On some devices, a system gesture near the screen edges (such as going back or opening notifications) can take priority over the page.

    Touches lag behind my finger

    A short delay is normal with power saving modes. Turn power saving off, close other apps and try again. A long or growing delay can point to a software problem or a failing screen.

    Frequently asked questions

    Can I test a touch screen on a computer?

    Yes. On a touch screen laptop or monitor, the test works like on a phone. Without a touch screen, you can use a mouse or trackpad to try the test, but it will not tell you anything about touch.

    Why does the test not go full screen on my iPhone?

    Safari on iPhone does not let web pages use full screen. The test still covers the whole browser window. For the most complete check, scroll to the top first so the address bar is as small as possible.

    Does a screen protector affect the result?

    It can. Thick or poorly fitted protectors can reduce sensitivity, especially at the edges. If you find a dead zone, repeat the test without the protector before concluding that the screen is faulty.

    What is the difference between a dead zone and a dead pixel?

    A dead zone is an area that does not respond to touch. A dead pixel is a point that does not display the right colour. They are separate parts of the screen: use our screen test to check the display itself.

    Is my touch data sent anywhere?

    No. The test runs entirely in your browser. Saved results stay on your device, and a result is only shared if you copy its link.

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