Muzzle is a free Mac menu bar utility that automatically enables Do Not Disturb when screen sharing begins, preventing notifications from appearing on screen during presentations, video calls, and meetings. (Free)
The app monitors active screen sharing sessions and silently activates Do Not Disturb without requiring any manual steps. When the screen sharing session ends, normal notification behavior resumes automatically. This addresses a common scenario where incoming messages, alerts, or banner notifications interrupt or expose private information during shared screens.
Muzzle integrates with major communication platforms including Zoom, Slack, Google Hangouts, Join.me, and BlueJeans. The app runs quietly from the menu bar with no persistent UI interaction required during normal use. Installation is straightforward: download the binary, place it in the Applications folder, and grant the necessary permissions.
The app was developed by Incident 57 and Bryan D K Jones, and is available as a direct download without App Store distribution.
System requirements: macOS 10.12 Sierra or newer. Available as a direct download (~1 MB) from muzzleapp.com.
Pricing: Free, no in-app purchases or subscriptions.
Limitations: Not distributed through the Mac App Store; installation requires a direct download and macOS security prompt bypass (right-click → Open on first launch). Does not offer granular notification filtering—all notifications are suppressed while screen sharing is active rather than allowing per-app rules. Platform support covers major conferencing tools but may not extend to all screen sharing or capture software. macOS Ventura and later versions include built-in Focus automation that partially overlaps Muzzle’s functionality.
Alternatives: macOS Focus modes (built-in, macOS Monterey+, configurable per-app automation), Quiet ($1.99) for general notification management without screen sharing detection, Hand Mirror ($10.99) for camera preview during calls with no DND features.
Suitable for users who frequently present, share screens, or join video calls and want automatic, hands-free notification silencing without configuring macOS Focus rules manually.
