Multi-touch test

When to test multi-touch

Test it if the device is for gaming, drawing or fast typing, or after a screen replacement. A screen that tracks too few fingers drops letters when you type, won't pinch to zoom properly and misses inputs in games. Put your fingers down one at a time, then move your whole hand.

Common faults and their causes

• Fewer touch points than normal: cheap replacement screens often track only 2 to 5 points, while most original phone screens track 5 to 10.
• Dots that jump or swap when two fingers are close: a low-quality touch layer, or interference from charging.
• Dots that vanish mid-swipe: a weak area of the touch layer. Run the full-screen touch test to find dead zones.

Some browsers and systems use multi-finger gestures for other things (a three-finger swipe to take a screenshot, for example). If the device captures the screen or switches apps, turn that gesture off and try again.

What to do if you find a fault

• Unplug the charger and test again.
• If a just-replaced screen tracks fewer points than before, tell the shop: it may be a cheaper screen than agreed.
• More on screens: the screen guide.