Time in every thermal state
Each change between nominal, fair, serious and critical is logged with timestamps. Today's stacked bar shows your share of time in each state.
Open source · macOS 14+ · Universal binary · System Monitoring
See why your Mac
runs hot.
HeatLedgerBar lives in your menu bar and records every change in your Mac's thermal state, then names the apps behind each hot period. Click the thermometer to see today at a glance.
Free & MIT licensed · Apple Silicon & Intel · Latest release
Features
A daily ledger of heat.
It tracks the official macOS thermal state over time instead of reading private temperature sensors.
Names the apps behind the heat
While your Mac is at fair or worse, per-process CPU is sampled every 10 seconds. Each hot period lists the frontmost app and the heaviest apps.
7 and 30 day history
A history window charts time per state over 7 or 30 days, with a per-day table and the top culprit for each day.
Alerts when heat lingers
Get a notification when your Mac stays hot for 5, 10 or 20 minutes, naming the heaviest app. You get at most one alert per hot period.
Thermometer in the menu bar
The icon is tinted gray, yellow, orange or red to match the current thermal state, so you can check it without opening anything.
Local data, no network
History is a JSON file on your Mac, kept for 7, 14 or 30 days. There are no accounts and nothing is sent anywhere.
Screenshots
See it in action.
Install
Up and running in a minute.
HeatLedgerBar is open source and not notarized with a paid Apple Developer ID, so macOS needs one extra step the first time.
- Download HeatLedgerBar-macOS.zip and unzip it.
- Move HeatLedgerBar.app to your Applications folder.
- Clear the quarantine flag once, then right-click the app and choose Open:
xattr -cr /Applications/HeatLedgerBar.app
- When prompted, allow notifications so HeatLedgerBar can warn you about long hot periods (System Settings Notifications) if you enable Launch at login, approve it under System Settings General Login Items.
Download
Get HeatLedgerBar for macOS
Free, forever. Built for macOS 14 Sonoma or newer, Apple Silicon and Intel.
Not notarized: on first launch right-click HeatLedgerBar.app → Open.
- macOS 14 Sonoma+
- Universal (Apple Silicon + Intel)
- MIT licensed · open source
- No ads, no accounts, no telemetry
- Built with Claude Code · how and why
FAQ
Questions, answered.
Is HeatLedgerBar free and open source?
Yes. It is free, released under the MIT license, and the full source is on GitHub. If you find it useful, there is an optional Support button that opens a Ko-fi page.
What permissions does it need?
Only notifications, which are optional and used for hot-Mac alerts, plus a login item if you turn on Launch at login. It does not ask for Accessibility, Screen Recording, Location or Full Disk Access.
Where is my data stored?
In a JSON file at ~/Library/Application Support/HeatLedgerBar/ on your Mac. Nothing leaves your machine, and you can erase it at any time with Clear History in Settings.
Why isn't the app notarized?
Notarization requires a paid Apple Developer account. Right-click the app and choose Open once to get past Gatekeeper, or build it yourself from source with Xcode.
Was this written by AI?
Yes. HeatLedgerBar was generated by Claude Code from a written spec as a clean-room reimplementation, with no code or assets from any commercial app. The full source is on GitHub under MIT, so you can read every line before you run it. It has had less human review than a hand-written app, so bug reports are welcome.
Support ❤️
Built by one person, given away for free.
HeatLedgerBar is a free, open-source alternative to paid utilities. If it earns a spot on your Mac, a coffee keeps the updates coming.
☕ Support Or on Ko-fi