Performance Monitor
A lightweight, open-source system monitor for your Mac's menu bar — CPU, memory, network, disk, GPU, temperatures, and battery at a glance.
Why this one?
🔒 Private by design
No telemetry, no analytics, no accounts. Nothing ever leaves your Mac — and because the source is public, you don't have to take our word for it.
🪶 Genuinely lightweight
A monitor that hogs the system it monitors is a bad joke. Sampling pauses when nothing is on screen, and heavy work stays off the main thread.
🆓 Free, and staying free
No paywalled features, no subscription, no nag screens. Updates are Ed25519-signed and verified before they install.
Install
brew install --cask inequitas/tap/performance-monitor
Or download the zip and drag to Applications. The app is not notarised (no paid Apple Developer ID — it's a free app): on first launch, right-click → Open. Requires an Apple Silicon Mac (M1 or later) on macOS 14+.
Everything at a glance
Deep detail windows
Per-core CPU, process breakdowns, latency and throughput charts, per-sensor temperatures, fan speeds, SSD wear level, and battery health.
Your menu bar, your rules
Pick which metrics live in the menu bar — as text or live sparklines — with optional threshold colouring when things run hot.
Alerts & history
Native notifications when CPU, memory, disk or temperature cross your thresholds. Optional CSV history for your own analysis.
Support the project ♥
Performance Monitor is free and will stay that way. If it saves you the price of a paid alternative, consider sponsoring on GitHub or buying a coffee on Ko-fi — it goes toward Apple's Developer Program fee so the app can be notarised. A ⭐ on the repo helps too.