Stylus support

This page collects the current stylus and pen-input behavior in Butterfly.

Supported platforms

• Android / mobile: Stylus input works best and is the main supported path today.
• Desktop (Windows/Linux): Stylus input is currently limited by Flutter input support.
• Web: Often a good fallback when desktop stylus behavior is inconsistent.

Stylus-related settings

You can find stylus-related options in Settings → Input → Pen:

• Pen-only input (changed in 2.5): helps avoid accidental finger/touch drawing when using a stylus.
• Pen-only toggle on stylus detection: when a stylus is detected, a quick Pen-only toggle is activated; you can still disable it in Settings → Input → Pen.
• Ignore pressure: useful when pressure data is unreliable. This is set to help with cases where Firefox reports incorrect pressure on first input.
• Input test: lets you verify what pointer/stylus events your device is currently reporting.

Pen shortcuts and pointer test

Butterfly supports pen/stylus shortcuts (button mappings can vary by device/OS). If shortcuts do not behave as expected, open Input test first and check button values:

• Primary button commonly appears as 10 (2)
• Secondary button commonly appears as 100 (4) or 100000 (32)

These values are bit mappings from pointer button flags.

Known framework limitations

Some stylus issues come from Flutter input handling rather than Butterfly directly.

• Android S-Pen tracking issue: flutter/flutter#42846
• Windows stylus issues: flutter/flutter#65248, flutter/flutter#102836
• Linux stylus issue: flutter/flutter#63209

If your setup is affected, please still report it in Butterfly issues with your platform, device model, and app version.