Graphics Tablet Pen and Stylus Test
An online tool for diagnosing an active pen: a tablet stylus, Apple Pencil, S Pen or Surface Pen. It shows more than the current Pointer Events values — it measures how many pressure steps actually reach the browser, how hard you must press before the pen starts drawing, and how often the tablet polls the pen. When pressure does not work, the tool names the cause — driver, Windows Ink mode or a pen reported as a mouse — instead of just showing a zero.
How to test your pen
Line thickness follows pressure. Pressure, tilt and button values update live under the canvas.
The Pressure tab draws a ramp curve: activation threshold, smoothness of the rise, and whether the pen hits its ceiling too early.
The Line tab measures deviation from a straight line, separately for fast and slow movement.
The Report tab collects the findings with their causes. Save it as an image, export JSON, or copy it as plain text for the manufacturer support ticket.
Check pressure, tilt, buttons and report rate right in your browser
Line thickness follows pressure. A perfectly even line means pressure never reaches the browser — see the report for the cause.
Three measurements run at once and on their own — there are no "start step" buttons: the checkmarks light up once enough data has arrived.
Tilt the pen in different directions without lifting it. The dot is the tip, the line is the body direction.
Trace the guide from end to end — first at a normal pace, then slowly. A slow diagonal is the most honest wobble test.
Sweep the pen across the whole tablet surface, edges included. Uncoloured cells are places no signal came from.
Findings are sorted by importance: what blocks your work first, then remarks, then reference notes.
