Touch Pressure Logger

How the Touch Pressure Logger Works

The Touch Pressure Logger records the pressure value of each contact on a scale from 0 to 1, on devices and pens that report pressure. Devices without pressure hardware report a fixed 0.5 while touching, which the tool flags.

1. Check support: The tool tests whether your device reports pressure that varies.
2. Press lightly and firmly: Touch or draw with different force. The pressure value updates live.
3. Read the log: Each row shows time, pressure, pointer type and position.
4. View the pressure graph: A line chart shows pressure over the length of each stroke.

Touch Pressure Logger Formula

The Touch Pressure Logger normalized pressure equals the raw sensor value divided by the sensor's maximum value. Browsers deliver this value as event.pressure.

Raw value

Sensor reading from the pen or screen

Max sensor value

Highest sensor reading, such as 4,096 levels

event.pressure

Normalized value from the browser

Example: A stylus with 4,096 levels reads 2,867. Pressure = 2,867 ÷ 4,096 = 0.70.

Touch Pressure Logger Reference Table

The Touch Pressure Logger conversion table converts normalized pressure into sensor levels and percent force.

About the Touch Pressure Logger

A Touch Pressure Logger is a data tool that records how hard a finger or pen presses on the screen, where the hardware supports it.

Pressure support depends on hardware. Active styluses such as Apple Pencil and Wacom pens report thousands of levels. Most phone screens report no finger pressure, and the Pointer Events standard sets pressure to 0.5 for active contacts on such devices.

Ways to Use the Touch Pressure Logger

The Touch Pressure Logger has 5 main uses, including stylus testing and drawing app calibration.

• ✓Stylus testing: Artists confirm a pen reports smooth pressure changes.
• ✓Drawing app calibration: Developers map pressure to brush width.
• ✓Hardware support checks: Users find whether a device reports real pressure.
• ✓Handwriting research: Researchers study pen force during writing.
• ✓Pen comparison: Reviewers compare pressure curves between stylus models.