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.
A graphic tablet has more moving parts than a stylus on a screen: a driver, an active area mapped to your display, a pen with its own sensor, and buttons the browser may never hear about. This is what to check, in the order that finds the fault fastest.
Connect the tablet over USB or pair it over Bluetooth, then draw inside the surface above while watching the cursor. On a graphic tablet you draw on the pad and watch the screen, so the cursor should jump to the matching spot the moment the nib touches down, rather than sliding over from where it already was. A cursor that slides is mouse mode, and nothing else on this page will read correctly until that is fixed.
Windows and macOS both ship a generic tablet driver that moves the cursor and reports nothing else, which is why a brand-new drawing tablet so often tests as a mouse. Install the driver from the manufacturer, reboot, and in its control panel check that the tablet is listed and that Windows Ink is enabled for it — on Windows that one setting is what carries pressure into a browser. On macOS, give the driver Accessibility and Input Monitoring permission in System Settings, or the pen will report position and nothing more.
Press from the lightest touch you can hold up to as hard as you would ever draw, slowly, and watch the pressure graph above. A healthy drawing tablet traces a smooth ramp that starts near zero and reaches full pressure before the nib bottoms out. A curve that jumps straight to the top has its driver pressure curve set too hard; one that never passes halfway has it set too soft, or the nib is worn down; a flat line at 0.5 means no force reading is arriving at all. The levels count tells you how many distinct steps the browser actually received, which is normally far fewer than the number printed on the box.
Draw along each edge of the pad and into all four corners. The active area is mapped to the whole screen by default, so a tablet mapped to the wrong monitor, or to an aspect ratio that does not match your display, shows up here as a cursor that stops short of one edge or sits offset from the nib. Every major driver can re-map the area or force the display's aspect ratio, and that is worth correcting before you suspect the pen.
Hold a barrel button down while you draw and the signals panel above will show whether the browser sees it. Browsers do receive the barrel button and the eraser tip, but not the express keys on the tablet body: drivers send those as ordinary keyboard shortcuts, so express keys staying silent here is expected rather than a fault. A barrel button that does nothing in any application is usually mapped to a keystroke in the driver instead of a right-click.
All of them look the same to a browser once their driver is installed, so this test works for any of them and no touchscreen is needed. What differs is the software: Wacom tablets use Wacom Center or the Wacom Tablet driver, while XP-Pen, Huion and Gaomon each ship their own. Those drivers conflict with one another, so uninstall the driver from any previous brand before installing a new one — two tablet drivers running at once is one of the most common reasons a drawing tablet that used to work suddenly reports no pressure. If the pen charges or takes a battery, check that too: a flat pen battery looks exactly like a dead pressure sensor.