Free and open source for macOS 15+

Know which app is slowing your Mac down.

OpenActivity folds every helper, renderer and background service into the app that started it. Nine hundred processes become the seventy-eight apps you actually run.

Download for macOS View on GitHub

Signed and notarized by Apple. No account, no analytics, nothing leaves your Mac.

The OpenActivity Overview page: CPU, memory, GPU, disk, network and energy cards with live graphs, plus memory and power by app.
0processes on a working Mac
0apps OpenActivity shows instead
0days of history, per app
0network requests, ever

Everything Activity Monitor doesn’t tell you.

One row per app, thirty days of memory, a menu bar that warns you, and the dev servers you forgot about.

Grouped by app

Chrome’s renderers count toward Chrome. A shell and everything it runs count toward Terminal. Expand any app to see its processes, and quit either one from any list.

Thirty days of history

Every metric charted for 12 hours, 24 hours, 7 days or 30 days, with the apps that used the most.

Lives in your menu bar

Figures, small graphs or an icon that turns into a warning sign when your Mac is under strain.

Dev servers, by project

Node, Python, Go, Ruby and Bun servers, grouped by the folder they run in, with their ports. Idle ones are flagged. Stop one, a project, or every idle server at once.

Alerts that mean something

A notification when an app pins the CPU, keeps growing, hammers the disk or saturates the network. You set the thresholds.

Volume per app

Turn one app down or mute it without touching the others. Nothing is recorded.

Sensors, fans and batteries

CPU and GPU temperatures, fan speeds, and the battery in your AirPods, mouse and keyboard.

Every page, real data.

Screens from a MacBook Pro running OpenActivity, not mock-ups.

The CPU page: load now and today, a bar for every core, a live chart and apps sorted by CPU with their process counts.

Load split into user and system, every core, today’s average and peak, and the apps behind it.

Forty seconds, all of it real.

Recorded from the app running on a Mac: the overview filling in live, the per-app CPU table, idle dev servers stopped in one click, the alerts, and the dashboard in the menu bar.

Next to Activity Monitor.

Activity Monitor is great at this second, one process at a time. OpenActivity adds who is responsible, what happened while you were away, and when to look.

Activity MonitorOpenActivity
The list showsEvery processEvery app, helpers included
HistoryLive graphs30 days, per app
AlertsNoneCPU, memory, disk, network
Menu barDock icon graphsFigures, graphs and a dashboard
Dev servers and portsNoneBy project, idle ones flagged
Temperatures and fansNoneIncluded
Volume per appNoneIncluded
Source codeClosedMIT licensed

What you run stays on your Mac.

No account, no analytics, no update checks. OpenActivity doesn’t make a single network request of its own. History is one SQLite file you can delete from Settings.

Install in about a minute.

  1. 1
    Download OpenActivity.zip from the latest release.
  2. 2
    Drag OpenActivity into your Applications folder.
  3. 3
    Open it. macOS asks once to confirm the download; choose Open.
Download for macOS Build from source

macOS 15 Sequoia or later. Apple silicon recommended. MIT licensed.