How to use it
- Open full screen for the whole display, or use the box on the page.
- Draw: put fingers down one at a time and move them. Watch the counter and check that every line follows its finger smoothly.
- Dead zone grid: slide a finger over every square. Squares turn green where the screen registers you. Pay attention to the edges and corners.
- Press Clear to start again. Exit full screen with the close button in the corner, or Esc on a keyboard.
Reading the results
- Most at once: the most touches your screen and browser reported at the same time. Phones and tablets commonly handle at least five; many laptops and tablets handle ten.
- Broken lines: the touch was lost for a moment. A few at the very edge can be normal; gaps in the middle are not.
- Dark squares that stay dark: a dead zone. Try each one several times, slowly, before you decide.
- Lines or dots you did not draw: ghost touches, where the screen reports a touch that did not happen.
The last touch line in the panel shows the contact size and, for pens and some screens, pressure. Not every device reports these.
If touches fail
- Clean and dry the screen and your hands. Water and grease cause missed and ghost touches.
- Remove the case or screen protector and test again; a thick or lifted protector is a common cause of dead spots.
- Unplug the charger and test again. Some chargers and cables can cause erratic touches.
- Restart the device. Check for system updates.
- If a dead zone stays in the same place after all that, it is likely a hardware fault; contact the maker or a repair shop.
Questions
How many touch points does my screen support?
Put down as many fingers as you can at once and read the Most at once counter. That is the number your screen and browser report together.
Why does it stop at three or four fingers?
Some phones and tablets use three, four or five finger touches for system gestures such as screenshots or switching apps, so those touches never reach the web page. Turn off those gestures in settings to test all fingers.
Does it work on a laptop touch screen?
Yes, in any modern browser. A mouse or trackpad also works, as a single touch.
What is a touch screen dead zone?
An area of the screen that does not respond to touch. The grid mode shows it as squares that stay dark.
Is my touch data sent anywhere?
No. Everything runs in your browser and nothing is sent or saved.