A native macOS menu bar app that blurs and dims everything except the active window, helping you focus.
Free, open-source alternative to Muffle.
- Blur inactive windows — GPU-accelerated Gaussian blur (adjustable 0–30)
- Dim inactive windows — semi-transparent dark overlay (adjustable 0–100%)
- Shake cursor to toggle — rapidly shake your mouse to enable/disable
- Menu bar only — lives in your menu bar, no Dock icon clutter
- Multi-display support — one overlay per screen, tracks the active window across displays
- Launch at login — optional, via macOS native login items
- Zero CPU at idle — event-driven architecture, no polling when nothing changes
- macOS 14.0 (Sonoma) or later
- Apple Silicon or Intel Mac
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Clone the repository:
git clone https://github.com/danielaustralia1/FocusBlur.git cd FocusBlur/FocusBlur -
Open in Xcode:
open FocusBlur.xcodeproj
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Build and run (⌘R)
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Grant Accessibility permissions when prompted, or manually:
- System Settings → Privacy & Security → Accessibility
- Add and enable FocusBlur
FocusBlur places a transparent overlay window on each display that sits above inactive windows but below the active one. The overlay applies a CIGaussianBlur filter via CALayer.backgroundFilters (GPU-composited) and a semi-transparent black tint for dimming. A rectangular cutout in the overlay lets the active window show through unblurred and undimmed.
The app uses the macOS Accessibility API (AXUIElement) to track the frontmost window's position and size in real time.
- Accessibility — Required to track the active window's frame via AXUIElement
- Screen Recording — Not required (uses CALayer background filters, not screen capture)
Inspired by Blurred by Dwarves Foundation and Muffle by Abjcodes.
MIT License — see LICENSE for details.