System Headroom Get System Headroom

A focused Mac utility for macOS 14+

See what’s using your Mac. Know what remains.

CPU, memory, and local listening ports—grouped by app, right from your menu bar.

Get System Headroom Explore the app
System Headroom Memory view with per-app values labeled RSS.
System Headroom CPU view showing 66% headroom and apps grouped by name.
System Headroom Ports view listing local TCP and UDP listeners by app.
Memory · CPU · Ports — light and dark mode.
Top 10 CPU and memory apps
14 → 1 Helpers become one app
3 views CPU, Memory, and Ports

Less noise

One app, instead of a wall of helper processes.

System Headroom recognizes related processes and rolls them into a single app row. Expand it when you want the details. Ignore them when you don’t.

Fourteen related processes consolidated into one Google Chrome row.
Familiar app names and icons make the answer readable at a glance.

Memory, named honestly.

The Mac App Store edition labels each app’s value as RSS—resident memory. That number can differ from Activity Monitor, especially for apps with shared or GPU-heavy helpers.

No mystery metric. No false promise of an exact Activity Monitor match.

Memory RSS is visible on every row
System Headroom Memory view with per-app values explicitly labeled RSS.

Built-in Help

Plain-language answers stay close.

Open Help for a quick glossary of headroom, RSS, ports, and grouped processes.

System Headroom Help window explaining headroom, RSS memory, and local ports.

TCPUDP

Know what is listening on your Mac.

The Ports view maps local listening ports to the app that owns them, then groups related listeners into one readable row.

  • Local listeners, not a history of every connection
  • Grouped by app with familiar icons
  • Refresh on demand or at your chosen interval
Dark mode Ports view listing local TCP and UDP listeners by app.
Ports view in dark mode.

Private by design

Your process samples stay on your Mac.

System Headroom needs visibility into local system activity to give you an answer. That information is not collected, tied to an account, or used to profile you.

Read the full privacy policy

System Headroom app icon

Version 1.0 · macOS 14+

A clearer answer is one click away.

Download System Headroom from the Mac App Store for a $4.99 one-time purchase.

Get System Headroom

No subscription. No account.

$ 4.99 one time

Good questions. Straight answers.

The practical details before you spend $4.99.

Is this an Activity Monitor replacement?

No. System Headroom is a focused companion for the quick answer: which apps are using CPU and memory, and which apps own local listening ports. Activity Monitor remains the deeper system tool.

Why can its memory number look different?

The Mac App Store edition reports resident memory and labels it RSS. Activity Monitor can use other accounting methods, so totals may differ—especially for apps with shared or GPU-heavy helpers.

Does it keep sampling when the popover is closed?

Sampling pauses when the popover is closed by default. If you enable live CPU in the menu bar, System Headroom keeps that value current while the app is running.

Can it quit or force quit another app?

No. The Mac App Store edition is monitoring-only. Its sandbox is designed for observation, not control of other apps.

Which Macs can run it?

System Headroom requires macOS 14 Sonoma or later.