Stylus & Pen Pressure Test

In short This reads pressure and tilt from a graphics tablet, an Apple Pencil or a Surface Pen through the browser's pointer events, and shows the latency between the pen moving and the line appearing. The most common result people ask about is pressure reading a constant 0.5: that is the value browsers report for a device with no pressure sensor, which means the pen is being treated as an ordinary pointer. On desktop this usually means the tablet driver is not installed or not running, or the browser is receiving mouse events rather than pen events. Reinstalling the manufacturer's driver fixes it more often than anything else. Tilt is patchier still — it requires support in both the hardware and the browser, and a blank tilt row is not necessarily a fault. On latency, what you can measure here is the browser's path and not the device's true response: a drawing application using native APIs will nearly always feel faster than the same pen in a web page, which is a limitation of the platform rather than of the pen.