Device Checks
Touchscreen Test — Multi-touch + Dead Spot Detector
Trace every touch on your screen. Detects dead spots, multi-touch capacity, and palm-rejection issues. Best on phone, tablet, or touch monitor.
Before you start
- 1 Open this page on a touchscreen device for best results.
- 2 Multi-touch mode: place 1-10 fingers on the canvas — each gets a colored dot.
- 3 Sweep mode: drag your finger across the canvas in a serpentine pattern. Untouched areas reveal dead spots.
- 4 Tap "Reset" to clear the canvas any time.
Active touches
0
Max simultaneous
0
Coverage
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Active touches
This device doesn't appear to be a touchscreen. Open this page on a phone, tablet, or touch-enabled laptop for the test to work. Mouse clicks won't trigger the touch handlers.
Frequently asked questions
How do I find a touchscreen dead spot?
Use the Sweep test below — drag your finger slowly across the entire screen in a serpentine pattern. Any area that doesn't paint a trail is a dead spot. Common causes: protective film with bubbles, water damage to the digitizer, cracked glass that severed the touch grid, or wear on a single area from heavy daily use.
How many simultaneous touches should my screen support?
Modern phones support 5-10 touches; tablets often 10. Older or budget devices may cap at 2-5. Many laptop touch panels and touch monitors support 10+. Run the Multi-touch test below — touch with all five fingers and see how many points appear. If it caps at 2, your hardware can only register two.
Why is my touchscreen registering ghost touches?
Three causes: (1) static buildup or moisture on the screen — wipe with a dry cloth; (2) damaged digitizer from drops or pressure; (3) faulty cable connection inside the device. Some screen protectors trigger ghosting too — try removing yours. If ghost touches happen at the same spot repeatedly, the digitizer is failing in that area and may need replacement.
How do I test palm rejection?
Touch the screen with one finger and hold it. While holding, rest your palm on the screen. A working palm-rejection algorithm ignores the larger contact patch (the palm) while keeping the finger active. Our visualizer shows all touch points — palm rejection working means the palm point disappears or never appears. iPad with Apple Pencil is the gold standard here.
Can I test a stylus this way?
Yes if your stylus uses standard touch input. Active styluses (Apple Pencil, Surface Pen, S Pen) use a different input pipeline (pointer events) that browsers may or may not expose — try our test, but if the stylus doesn't appear, your browser doesn't pass it through. Capacitive 'dumb' styluses just register as small finger touches and work fine.
Does this damage my screen?
No. Touch tests only read what your screen reports — they don't drive the digitizer harder than normal use. The Sweep test asks you to drag continuously, which is exactly what scrolling does many times a day. Safe for any screen.
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