MenuMeter

A tiny, free stereo level meter for the macOS menu bar. It shows how loud everything your Mac is playing is, live, with two slim bars — one per channel.

• Whole-system audio — meters every app at once, on whatever output you're using (speakers, headphones, AirPods). Switches automatically when you change output.
• No extra drivers — uses the Core Audio process taps built into macOS 14.2+. Nothing like BlackHole or Loopback needed.
• Peak hold and clip lights — a thin line marks each channel's recent peak, the tip of the bar glows orange-red above −4 dB, and the dot at the end lights red for two seconds when a channel hits 0 dB.
• Per-app volume — the menu has a volume slider for every app that's playing, so you can turn one down without touching the rest. MenuMeter remembers each app's volume.
• Colours — Yellow, Green, Blue, Pink, your system accent colour, or Monochrome, with saturation and brightness sliders to fine-tune it. Adapts to light and dark menu bars.
• Light on resources — about 2% of one CPU core while audio plays, close to nothing when it's silent, and around 25 MB of memory.
• Open at Login — one click in the menu.
• Nothing is recorded — audio is only measured to draw the meter, never stored or sent anywhere.

Requirements

macOS 14.2 (Sonoma) or later.

Install

Download

1. Download MenuMeter.zip from the latest release and unzip it.

2. Move MenuMeter.app to your Applications folder.

3. The app isn't notarized by Apple, so the first time, right-click it and choose Open, then confirm. If macOS says the app is damaged, clear the download flag instead:

   xattr -dr com.apple.quarantine /Applications/MenuMeter.app

4. When asked, allow MenuMeter to record system audio. This is how it measures levels; without it the meter stays empty. You can change this later in System Settings → Privacy & Security → Screen & System Audio Recording.

Build from source

Needs the Xcode Command Line Tools (xcode-select --install).

git clone https://github.com/bassepeder/MenuMeter.git
cd MenuMeter
./build.sh
ditto MenuMeter.app /Applications/MenuMeter.app
open /Applications/MenuMeter.app

Usage

Click the meter for the menu: set the volume of any app that's playing, choose a Color and fine-tune its saturation and brightness, turn on Smooth Animation (60 fps) or Open at Login, or Quit. To move the meter, hold ⌘ and drag it; macOS remembers the spot.

MenuMeter is cheap to run: about 2% of one CPU core while audio plays at 30 fps (3% at 60 fps), and close to nothing when it's silent. It moves Core Animation layers instead of redrawing, because every redraw makes macOS re-render a copy of the menu bar item for each display.

Customizing

The meter lives in main.swift, per-app volume in AppVolume.swift:

• Size and position — barWidth, barHeight, gap, dot and verticalOffset in MeterView.
• Colours — the MeterColor enum.
• Scale and movement — floorDB (the bottom of the scale, −40 dB by default), the release speed and peak-hold time in Channel.update.

Run ./build.sh again after any change. Each rebuild is a new ad-hoc signature, so macOS asks for the audio permission again.

How it works

MenuMeter creates a private, global stereo Core Audio process tap, wraps it in a private aggregate device clocked by your current output, and reads the peak level of each channel on the audio thread. To change an app's volume, MenuMeter taps just that app, which silences its normal output, and plays the tapped audio at the volume you set. At 100% the app is left alone. The meter updates 30 times a second (60 with Smooth Animation) with fast attack, smooth release (about 24 dB/s) and a 1.2-second peak hold.

The look is inspired by the menu bar meter in Rogue Amoeba's Audio Hijack. MenuMeter is not affiliated with Rogue Amoeba.

License

MIT