macOS uses FN/Globe key to show an input source picker popup, which is slow and distracting. FnLangSwitch replaces that with a direct, instant toggle between your keyboard layouts.

A minimal macOS app that switches your keyboard input source (language) when you press the FN key. No popups, no delays — instant, invisible switching. The app runs in the background with no dock icon and no menu bar icon.

Download the latest version from GitHub Releases.

1. Go to System Settings > Keyboard and set "Press globe key to" to "Do Nothing". This prevents macOS from showing its own input source picker when you press FN.
2. Launch the app
3. Press FN to toggle between your input sources. That's it.

• Monitors the FN key via NSEvent.addGlobalMonitorForEvents(matching: .flagsChanged)
• Switches input sources using the Carbon TISSelectInputSource API