A per-application volume mixer for the macOS menu bar — the Windows-style "one slider per app" mixer macOS has never shipped natively.
Click the menu bar icon to see every application currently playing audio, each with its own volume slider and mute toggle, without touching the system-wide volume or any other app.
macOS has no built-in way to turn down just one noisy app (a browser tab, a chat notification) without affecting everything else. Windows has had this for over a decade. This is a small, personal project to fix that — and to learn Swift/SwiftUI/Core Audio along the way.
- macOS 14.4 (Sonoma) or later, Intel or Apple Silicon
- Xcode 15.3+ (to build and run)
Built on the public Core Audio Process Tap API
(macOS 14.2+): each controlled application gets a private Aggregate Device combining a tap on its
audio with the real output device, and a running AudioDeviceIOProc that scales the captured
samples by the chosen volume (or silences them when muted) before writing them to the speakers.
Some rows you'll see aren't a single "app" in the traditional sense. For example, WebKit GPU is a shared process from the WebKit framework, used by any app with an embedded web view (Safari, Mail, Notes, and others) — it isn't launched as a child process of one specific app, so it can't be reliably folded into a single app's row. It's shown as its own entry rather than guessed into the wrong app.
Multi-process apps that do spawn their own helpers as child processes or bundle them inside
their own .app (Chrome and most Chromium-based browsers, for example) are correctly grouped
under one row.
This is a personal project built while learning Swift, SwiftUI, and Core Audio — it's very much a work in progress, and I'm still learning as I go. If you download it and hit a bug, a crash, or something that just feels wrong, please open an issue — real reports from real machines are genuinely valuable and appreciated.
MIT — see LICENSE.