Why this tool is useful
Use this surface to check whether a phone, tablet or touch monitor reports multiple contacts and releases each pointer cleanly without stuck touches.
Browser & Privacy · runs locally
Multi-Touch Screen Tester
Visualize concurrent touch or pen contacts, pressure and pointer coordinates inside a bounded local test surface.
Ready. Your working data stays in this browser.
How it works
Pointer Events are tracked only inside the panel. Active contacts are keyed by their temporary pointer ID, capped in memory and removed on pointerup or pointercancel.
Practical example
Place two fingers on the panel, move them apart and lift both. The active-contact count should rise to two and return to zero while coordinates update independently.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.