About the S Pen and Stylus Test
The S Pen and Stylus Test is a comprehensive diagnostic tool designed to evaluate the functionality of your active stylus, such as Samsung's S Pen, Apple Pencil, or other pressure-sensitive styluses. This tool helps you verify if your device's digitizer is correctly tracking the pen and registering its pressure levels.
What does this tool test?
- Stylus Detection: Verifies if your device correctly identifies the input as a "pen" rather than a regular "touch" from a finger.
- Tracking Accuracy: Allows you to draw freely to check for any dead zones, jitter, or skipping in the tracking area.
- Pressure Sensitivity: Measures and displays the exact pressure level (from 0.00 to 1.00) registered by the stylus, testing if the pressure sensor in the pen is functioning properly.
How to use the test
- Take out your S Pen or active stylus.
- Begin drawing or writing on the canvas area above.
- Observe the "Pressure" value as you press harder or softer on the screen. The drawn line thickness should also change dynamically.
- Try touching the canvas with your finger. The tool should detect this and prompt you to use your stylus instead.
- Once you have verified the tracking and pressure, use the Pass/Fail buttons to record your result.
Troubleshooting Stylus Issues
If your stylus is not functioning correctly, consider the following steps:
- Check the tip: Worn or damaged nibs can cause poor tracking or pressure sensing. Try replacing the tip.
- Clean your screen: Dirt, oils, or certain screen protectors can interfere with the digitizer.
- Check for updates: Ensure your device's software is up to date, as well as any specific apps for your stylus (like Samsung Notes or Apple Pencil settings).
- Battery level: Some active styluses require a battery. Make sure it is charged or the battery is replaced. (Note: standard S Pens do not need a battery for basic drawing, only for Air Actions).
- Magnetic interference: Cases with strong magnets can cause dead zones or wavy lines on digitizer screens. Try removing the case and testing again.
Frequently asked questions
Why is my S Pen not writing on the screen?
Remove any thick or non-compatible screen protector, check the S Pen tip for wear and replace it if it is flat, and make sure you are using the correct pen for your model. Z Fold S Pens have a different tip than Galaxy S Ultra S Pens.
Why don't S Pen Air Actions work on my Galaxy?
Air Actions need a Bluetooth-enabled S Pen. The S Pen included with the Galaxy S25 Ultra no longer has Bluetooth, so remote gestures and the camera shutter button are not available with it, while writing and hover still work.
Does this test work with Apple Pencil?
Yes. On iPad, Safari reports Apple Pencil input as a stylus with pressure and tilt, so the drawing pad shows those values. Pressure support depends on your Apple Pencil model.
How do I test S Pen pressure sensitivity?
Draw slowly while gradually pressing harder. The line should get thicker smoothly and the pressure percentage should rise. Jumps from thin to thick, or a constant 50% reading, point to a worn tip or a digitizer problem.