Check pen pressure, tilt, jitter and palm rejection right in your browser. Works with Apple Pencil, Samsung S Pen and Surface Pen, and with Wacom, XP-Pen and Huion graphics tablets — nothing to install.
Waiting for pen input
Touch your stylus to the screen, or move it just above your graphics tablet. Nothing can be measured until the first pen event arrives: no browser will say whether a stylus exists before one is used.
Apple Pencil, Samsung S Pen, Surface Pen and pens from Wacom, XP-Pen and Huion all work here. A desktop with no touchscreen is fine — a graphics tablet reports as a pen on its own.
Draw here with your stylus. The stroke thickens as you press — try one stroke that goes from feather-light to as hard as you dare.
Draw a stroke to test pen pressure
Only a stylus draws on this page: a mouse or a finger is ignored on purpose, so nothing can be mistaken for a pen.
A stylus is four separate measurements pretending to be one device: how hard you press, which way you lean it, how straight it draws, and what the screen does with your palm while you work. Each of them fails on its own, and each of them is checked separately above.
Every pen event carries a pressure between 0 and 1, and drawing apps turn that number into stroke width, opacity or brush hardness. The catch is that the number always exists: when a device has no force sensor, the pointer specification tells the browser to report exactly 0.5 while the tip is down. That is why a flat 0.5 is never proof of pressure support, and why this test refuses to call anything a pass until the readings have actually moved.
Apple Pencil, Samsung S Pen, Surface Pen and nearly every graphics tablet pen also report the angle they are held at — as tiltX and tiltY, as altitude and azimuth, or as both, depending on the browser. Shading brushes and calligraphy nibs live on those values. A pen with no tilt sensor still reports a perfectly upright zero rather than nothing at all, so only a reading that leaves the vertical proves the sensor is there.
Jitter is the ripple a stylus leaves on a slow line that should be straight. It comes from the digitizer interpolating your position between its sensor wires, so it shows up on slow diagonals and hides on fast strokes, horizontals and verticals — which run along the sensor grid. Cheaper tablets and some pen displays wobble by several pixels; a healthy one stays within about one. It is a hardware trait, not usually a driver bug.
While the pen is in range, a well-behaved device stops reporting the hand resting on the glass. This page counts every touch contact that arrives while the tip is down, so you can lean on the screen the way you normally would and see what gets through. Hover is the other half: the pen is detected before it lands, which is what puts a cursor under an unlanded Apple Pencil. No browser exposes how far away the pen is — only that it is close.
A graphics tablet needs no touchscreen: its driver presents the pen to the system, and the browser sees ordinary pen events. If this page never leaves the waiting state with a tablet plugged in, the pen is being delivered as a mouse — install the manufacturer's driver rather than relying on the generic one, and on Windows check that Windows Ink is enabled for the tablet, since that is what carries pressure into browsers.
Applications read the pen through different paths: Windows Ink, the older Wintab interface, or plain mouse input. A drawing app set to Wintab can have perfect pressure while the browser, which uses Windows Ink, gets none — and the reverse happens just as often. If pressure works here but not in your app, the fix is in that app's tablet settings; if it fails here too, it is the driver or the pen.