Default0 is a macOS menu bar utility focused on one core problem: preventing embarrassing sound leaks when you forget to mute.
Unexpected speaker output often happens in transition moments, not when you are actively managing audio, such as unlocking your Mac, switching audio devices, losing Bluetooth audio, changing Wi-Fi networks, or opening specific apps. Default0 automatically mutes at these high-risk moments before sound plays out loud.
Key Features
- Mute on screen unlock - Automatically mutes after your screen is unlocked so your first click does not become an accidental out-loud moment
- Mute on audio output change - When the default audio output changes, Default0 mutes immediately to avoid leaks during speaker-headphone transitions
- Mute on Bluetooth audio disconnect - If a Bluetooth audio device disconnects, audio is muted before it falls back to speaker output
- Mute on Wi-Fi change - When Wi-Fi connects, disconnects, or switches networks, Default0 can trigger mute to prevent connectivity-driven speaker surprises
- Mute on first login after startup - During the first login phase after startup, mute is applied to reduce accidental playback risk
- Mute on app open (Pro) - Set high-risk apps such as meeting, video, social, or entertainment apps to auto-mute when they become active
Default0 is lightweight, menu bar first, and quick to configure. It is designed for meetings, open offices, classrooms, libraries, shared spaces, and any situation where accidental speaker output can cause disruption or embarrassment.






