Fabar — macOS Per-App Volume Control

A lightweight, high-performance macOS menu bar app that lets you adjust the volume of individual applications independently.

Website: fabar.gigaptera.com · Download: Latest release

If Fabar is useful to you, please consider giving it a ⭐ — it helps the project reach more Mac users and supports ongoing development.

Features

• 🎚️ Per-App Volume Control — Adjust volume for any application independently
• 🔊 Boost Quiet Apps up to 200% — Not just attenuation; amplify apps that are too quiet
• 🔇 Mute Individual Apps — Silence specific apps without affecting master volume
• 💾 Persistent Settings — Your volume preferences are saved and restored
• ⚡ Lightweight — ~30 MB memory footprint, minimal CPU
• 🎧 Plays Nice with Audio Gear — Designed to play nicely with USB/Thunderbolt interfaces and Multi-Output/aggregate devices such as BlackHole; devices are never reconfigured
• 🔄 Auto-Update — Checks for updates automatically; manual check via ⋯ → Check for Updates…
• 🎯 Menu Bar Only — No Dock icon, zero visual clutter
• 🌏 English & Japanese — fully localized UI

How Fabar Compares

	Fabar	BackgroundMusic	FineTune	SoundSource
Price	Free	Free	Free	$49
License	MIT	GPL-2.0	GPL-3.0	Proprietary
Architecture	Process tap	Virtual driver	Process tap	Virtual driver
Installs a driver	No	Yes	No	Yes
Unadjusted apps	Native path	All routed	Native path	All routed
Volume boost	200%	—	400%	✓
Per-app routing	—	—	✓	✓
EQ / effects	—	—	✓	✓
Install	DMG	DMG / brew	brew	DMG
macOS	14.4+	10.13+	14.2+	15+

Fabar focuses on one thing: simple, per-app volume from your menu bar. If you need EQ, per-app output routing, or audio effects, SoundSource and FineTune are great choices. If you want the lightest tool that doesn't touch your system audio stack, that's Fabar.

Installation

Option 1: Download DMG (Easiest) ⭐

1. Download the latest Fabar.dmg from Releases
2. Open the DMG file
3. Drag Fabar.app to /Applications
4. Launch Fabar from Applications

The first time you adjust an app's volume, macOS asks for the Audio Recording permission — Fabar needs it to process other apps' audio (System Settings → Privacy & Security → Audio Recording).

Option 2: Build from Source

Requires Xcode 16+ and xcodegen (brew install xcodegen):

git clone https://github.com/gigaptera/fabar.git
cd fabar/fabar-app
./build.sh

Output: Build/Fabar.app — copy to /Applications.

See DEVELOPMENT.md for detailed setup and production builds.

Requirements: macOS 14.4 (Sonoma) or later, Apple Silicon or Intel Mac

How It Works

Fabar uses Core Audio Process Tap to intercept app audio, adjust gain, and re-render it to the output device. This approach:

• ✅ Works with any app (Spotify, Slack, Chrome, etc.)
• ✅ Supports USB/Thunderbolt devices without distortion
• ✅ Preserves audio quality — when the tap and device share a sample rate there is no resampling; gain is the only processing applied
• ✅ Apps you never adjust stay on the native audio path, completely untouched
• ✅ Adjusted apps run through a ~30 ms buffer — imperceptible for music and video

For technical details, see ARCHITECTURE.md.

Privacy

Fabar requires macOS Audio Recording permission because Core Audio Process Tap needs it to process other apps' audio. Fabar does not record, save, upload, or transmit your audio. Audio is processed locally on your Mac only for volume adjustment.

Compatibility Testing

Fabar is currently being validated across different macOS versions and audio setups.

Tested by the maintainer:

• macOS 14.4+
• Built-in speakers
• BlackHole
• Multi-Output Devices

Looking for reports from:

• macOS 14.4, 14.5, 15.x, and newer versions
• Apple Silicon and Intel Macs
• AirPods / Bluetooth devices
• USB / Thunderbolt audio interfaces
• OBS, DAWs, Discord, Zoom, browsers, music apps

If you try Fabar, please open a Compatibility report.

Known Limitations

• Per-app output routing: Not supported — adjusted apps play on the system default output. This only matters if you've explicitly pointed an app (a DAW, Zoom, etc.) at a different device inside that app; everything else follows the default and is unaffected
• Per-tab volume: Not implemented (requires browser extension)
• AirPods / Bluetooth: Inherent latency from the Bluetooth stack; adjusted apps may briefly glitch right after switching output devices while sessions rebuild

See LIMITATIONS.md for workarounds and detailed explanations.

Documentation

• ARCHITECTURE.md — How the audio pipeline works
• LIMITATIONS.md — Known issues and workarounds
• DEVELOPMENT.md — Build, test, and contribute

Scopes

Fabar Lite (Current)

• Per-app volume adjustment
• Per-app mute
• Persistent settings
• Login item toggle

Fabar Lite Plus (Planned, Separate App)

• Per-app output device selection
• Advanced routing

Contributing

Bug reports, feature ideas, and pull requests are welcome — see CONTRIBUTING.md for the workflow and DEVELOPMENT.md for build instructions. For security issues, see SECURITY.md.

Support Fabar

Fabar is free and will always be free. Here's how you can help:

• ⭐ Star this repo — helps Fabar reach more Mac users
• 🧪 Open a compatibility report — helps us validate across setups
• 🐛 File issues and PRs — see CONTRIBUTING.md
• ☕ Buy Me a Coffee — funds development and hardware testing

See SPONSORS.md for details.

License

MIT License — see LICENSE for details.