How to Test a Touch Screen

How do I check my touch screen with this test?

Press Full screen, then drag one finger along every row of the grid until it reads 100%. A cell that will not fill, or a line that breaks, marks a dead spot.

Then put down two, three or more fingers at once. If Most at once stays lower than the fingers you used, the screen is missing touches.

How do I check a touch screen on Windows?

Windows tells you whether it sees a touch screen at all. Follow these steps:

1. Open Settings, then System, then About.
2. Under Device specifications, read the Pen and touch line. It says whether touch is supported and how many touch points Windows sees.
3. If touch lands in the wrong place, search the Start menu for Calibrate the screen for pen or touch input.

If Pen and touch says no touch input is available, check that the touch driver is installed in Device Manager.

How do I check a touch screen on Android?

Android has a hidden setting that draws every touch on screen. It works in any app:

1. Open Settings, then About phone, and tap Build number seven times to turn on Developer options. On Samsung phones, Build number is under Software information.
2. Open Developer options and turn on Pointer location. Every touch now draws a line and shows its position.
3. Drag a finger along each edge and across the middle, and look for breaks in the line.
4. Turn Pointer location off again when you finish.

How do I check a touch screen on an iPhone?

iPhones have no built-in touch test, so start with Apple’s basic fixes and then use the grid above.

1. Restart the iPhone, which clears most touch problems.
2. Clean the screen with a soft, slightly damp cloth, and dry your hands.
3. Take off the case and screen protector, and unplug anything in the charging port.
4. Run the test on this page in Safari and draw over the whole grid.

If the same area still fails, book a repair with Apple or a trusted shop, and show them the grid.

What do the results mean?

Each fault points to a different cause:

• One dead strip or corner: usually damage to the touch layer, so the screen may need replacing.
• Touches in the wrong place: often a calibration or driver problem that settings can fix.
• Dots you did not draw: often dirt, water, a loose screen protector or a faulty charger.
• Lag everywhere: usually the device is busy, so close apps and restart.

How do I test a touch screen before buying a used phone?

Test it in person, before you pay. These checks take about five minutes:

1. Take off the case and screen protector, if the seller agrees.
2. Open the touch screen test in full screen and cover the whole grid.
3. Trace slowly along every edge and into each corner.
4. Put down several fingers at once and check the count.
5. Run our dead pixel test to check the display as well.

Also confirm the model, so you know the screen is the size it should be. Our iPhone screen sizes list every model’s screen.

How do I stop ghost touches?

Ghost touches are taps you did not make. Work through these fixes in order, testing after each one:

1. Clean and dry the screen and your hands.
2. Remove the screen protector, especially if it is lifting or cracked.
3. Unplug the charger, and try a different charger and cable.
4. Restart the device and install any updates.
5. On Android, start in safe mode to see whether an app is the cause.

If ghost touches go on with all of that done, the touch layer may be faulty. Back up your data before any repair or reset.

Does a screen protector affect touch?

A good one should not. Thin glass or film made for your exact model passes your touch through with no change you can feel.

Problems start when the protector does not fit well. Watch for these signs:

• bubbles or dust under the protector,
• edges that lift or catch the case,
• a crack across the protector,
• very thick glass that misses light taps.

Replace it with one made for your model, and run the test again with it on.

Is it worth repairing a touch screen?

Check your warranty and insurance first, since a fault you did not cause may be covered. Take a photo of the test grid to show the dead area.

On many modern phones, the glass, touch layer and display are joined as one part. That means a touch repair usually replaces the whole screen, so get a quote before you decide.

How do I keep a touch screen clean without damaging it?

Turn the screen off, then wipe it with a soft microfiber cloth. For stubborn marks, dampen the cloth a little with water or a screen cleaner.

Never spray liquid straight onto the screen, as it can run into the edges. Skip paper towels and strong cleaners, which can scratch or strip the coating.

How do I calibrate a touch screen on Windows?

If touches land a little off from your finger, calibration can line them up again:

1. Open Control Panel and search for Calibrate.
2. Choose Calibrate the screen for pen or touch input, then press Calibrate.
3. Tap each crosshair as it appears, then save the result.

Run our touch screen test again afterward to check the edges and corners.

What should I test on a touch screen laptop?

Test the corners and the edge near the keyboard, where the hinge flexes the screen. Then try a two finger pinch and scroll in a browser.

Check the display too, as touch faults and pixel faults are separate. Our dead pixel test covers the screen itself, and the laptop screen size chart lists each size.