Stylus / Pen Pressure Test

How to use it

1. 1

   Draw a long stroke, starting light and pressing harder as you go. The line should thicken smoothly.

2. 2

   Watch the pressure figure, not just the line. It runs from 0.00 to 1.00, and it should move continuously rather than jump.

3. 3

   Tilt the pen while drawing. Tilt is reported in degrees on two axes by devices that support it, and stays at zero on devices that do not.

4. 4

   Twist the barrel if your pen supports it. Very few do, and the reading says so rather than pretending.

Reading the pressure figure

A pen that reports pressure gives a range of values as you press. A device that does not support pressure reports 0.50 for every contact, because that is the value the standard uses for "pressed, no sensor". Those two look identical in a drawing, which is why the reading is spelled out in words underneath rather than left to you to interpret.

If the figure jumps straight from 0.00 to 1.00, the pen is being treated as a plain contact. That usually means the wrong driver, a pen that needs pairing before pressure works, or a browser that does not pass the pen's data through.

What this page cannot do

It cannot tell you how many pressure levels your pen has. Manufacturers quote figures like 4,096 levels, but a browser receives a single number between 0 and 1 with no indication of how finely it was measured, so any such count from a web page would be invented. It cannot measure latency or accuracy either, and it cannot fix a pen that needs new batteries, a new nib or its own driver.

For the screen underneath the pen, use the Touchscreen Test; for a laptop's pad, the Trackpad Test.