How this test works
Draw across the full screen and tap the edges to reveal missed or interrupted touch input.
- Prepare the display using the checklist below.
- Select Start test and allow fullscreen mode if your browser asks.
- Use the arrow keys, on-screen controls, or click the pattern to move through the test.
- Exit the runner and save a local observation if useful.
Before you begin
- Clean and dry the screen
- Remove gloves unless the display supports them
- Place the device on a stable surface
What to look for
- Gaps while dragging a finger
- Edges or corners that do not respond
- Incorrect or missing simultaneous touches
Important: This tests pointer events delivered by the browser. Operating-system gestures, palm rejection, browser chrome, and hardware drivers can affect input.
Frequently asked questions
Can this detect dead touch zones?
It can reveal areas where browser pointer events are not received consistently.
Does it support multi-touch?
Yes, the counter shows simultaneous browser pointer contacts when the device and browser support them.
Why do edge gestures leave the page?
Some edge gestures are reserved by the operating system and may never reach the browser.