How to run the touch screen test
- Clean the screen and dry your hands. Water, grease and a peeling screen protector cause most false results.
- Remove the case if it covers the screen edges, and unplug the charger (a faulty charger can cause erratic touches).
- Start with the grid test. Swipe slowly over every square, row by row, including the very edges and corners. Each square turns green when it registers a touch.
- Go back over any dark squares two or three times. A square that never turns green is a dead zone.
- Run the other tests if you have a specific problem: the draw test for jumpy or broken lines, multi-touch for pinch-zoom problems, and the ghost touch test if your phone taps things on its own.
The four tests explained
Grid test: find dead zones
The screen is divided into finger-sized squares. If touch works everywhere, the whole grid turns green. Dead zones usually show up as a strip or patch that stays dark, often along an edge or where the screen was cracked or pressed.
Draw test: spot gaps and jitter
Draw slow straight lines and circles across the whole screen. A healthy touchscreen draws smooth, unbroken lines. Gaps, jumps to another spot, or wobbly lines in one area point to a weak section of the touch layer.
Multi-touch test
Place several fingers on the screen at once. Each touch gets a numbered circle, and the page records the highest number tracked at the same time. If pinch-to-zoom or two-finger gestures feel unreliable, this shows whether the screen is losing fingers.
Ghost touch test
Start it, put the device on a table and don't touch it for 30 seconds. Any touch the screen registers in that time is a "ghost touch" and appears as a red dot. A few red dots in the same place are a strong sign of a hardware or screen protector problem.
What your results mean
| Result | Likely cause | Try this |
|---|---|---|
| Dark strip along one edge | Case or screen protector pressing the edge, or edge damage | Remove case and protector, test again |
| Dark patch where the screen was cracked | Damaged touch layer (digitizer) | Screen repair is usually needed |
| Lines jump or break in one area | Weak or damaged section of the touch layer | Restart, remove protector; repair if it persists |
| Fewer fingers tracked than expected | Screen protector, dirty screen or digitizer fault | Clean the screen and retest without the protector |
| Red dots in the ghost touch test | Moisture, faulty charger, bad protector or hardware fault | Dry the screen, unplug the charger, restart, retest |
iPhone touch screen test tips
The iPhone touch screen test works in Safari or Chrome. Turn on rotation and test in both portrait and landscape: Safari keeps a thin bar at the top or bottom, and rotating moves it so you can check the area underneath. If your iPhone responds badly only while charging, try a different cable and power adapter before blaming the screen.
Android phones and tablets
On Android, the touch screen test online works the same way in Chrome, Samsung Internet or Firefox. Some brands also include a hidden hardware diagnostic menu, but how you open it differs from brand to brand, while this page works on every device. If you find a dead zone, restart the phone and run the grid test again before deciding it's a hardware fault; a frozen app or an aggressive battery saver can make the screen feel unresponsive too.
How we tested this tool
We checked the touch screen test in Google Chrome on Windows (using a mouse, which the page treats like a single finger) and in a mobile-size browser view: the grid fills green as you swipe, fast swipes don't skip squares, the draw test draws continuous lines, and the full-screen view can be closed with the ✕ button or the Esc key. We don't have results from real phones yet. Tried it on yours? Tell us how it went and we'll add your results here.
Frequently asked questions
How do I know if my touch screen has a dead zone?
Run the grid test and swipe over every square. Squares that stay dark even after several slow passes are areas where the screen isn't registering touch. If the same spot fails every time, it's a dead zone.
What is a ghost touch?
A ghost touch is when the phone reacts as if someone tapped the screen when nobody did: apps open, text appears or the screen scrolls by itself. It is often caused by a dirty or wet screen, a poor screen protector, a faulty charger, or damage to the touch layer.
Is there a built-in touch screen test app Android phones can use?
Some Android brands include a hidden hardware test menu, and Samsung's Members app has a diagnostics section. The option and how to reach it depend on the brand and model, so a browser-based test like this one is often the quickest option because it works the same on every phone.
Does the iPhone touch screen test work in Safari?
Yes. All four tests work in Safari and Chrome on iPhone and iPad. Safari can't hide its address bar completely, so test the area behind it separately by scrolling or rotating the phone.
How many fingers should multi-touch detect?
Most modern phones and tablets detect at least 5 touches at once, and many detect 10. This page shows both the number your device reports and the highest number it actually tracked during the test.