A tiny temperature monitor that lives in your menu bar.
Mercury reads temperatures directly from your Mac's SMC (System Management Controller) and displays them in the menu bar.
- Native - Built with SwiftUI and IOKit. Nothing else.
- Fast - Direct SMC reads. Sub-millisecond sensor polling.
- Light - <1% CPU at default refresh rate. No network calls.
- Minimal - One menu bar item. No dock icon. No windows.
- CPU, GPU, and Battery temperature monitoring
- Dynamic menu bar icon (low / medium / high)
- Celsius and Fahrenheit
- Configurable refresh interval (1~10s)
- Auto-detects available sensors per chip
- Supports Apple Silicon (M1~M5) and Intel
brew install --cask uhojin/tap/mercury
Or add the tap first:
brew tap uhojin/tap
brew install --cask mercury
Download the latest .dmg from Releases, open it, and drag Mercury to Applications.
Note: Mercury is not code-signed. On first launch, right-click the app and select Open, then click Open in the dialog.
git clone https://github.com/uhojin/mercury.git
cd mercury
xcodebuild -scheme Mercury -configuration Release build
The built app will be in ~/Library/Developer/Xcode/DerivedData/Mercury-*/Build/Products/Release/Mercury.app.
- macOS 14 (Sonoma) or later
- Apple Silicon or Intel Mac
Mercury has only been tested on an M1 Pro MacBook Pro. It should work on other Apple Silicon and Intel Macs, but sensor availability and key mappings may vary. If you run into issues on your machine, please open an issue.