How to stop one app from slowing down everything else on your Mac

27 October 2026 · 5 min read

To stop one app from slowing down everything else on your Mac, first find it, then choose one of three things: quit it, freeze it, or slow it down. Quitting is the cleanest. Freezing stops it completely until you resume it. Slowing it down, which Foreman calls Efficiency Mode, keeps the app open but holds it to about a quarter of the processor time it would take while it is in the background, and gives it full speed again when you bring it to the front.

First, find the app

You cannot fix what you have not found, and the slow app is often not the one you suspect. Open the Force Quit window with Option-Command-Escape (⌥⌘⎋): an app that has stopped responding has “(not responding)” after its name. If not, you need a list that shows use per app.

In Foreman, press Control-Shift-Escape (⌃⇧⎋), go to Processes and click the CPU header to sort from highest. The top row is the one taking the most processor time. Apps are grouped with their helper processes, so a browser’s many helpers add up to one row you can read. Check Memory and Disk the same way, because an app can hurt the Mac by using memory or the disk and not the processor. Why is my Mac so slow: how to find the app to blame covers the whole method.

Before you do anything to it, ask two questions. Is it busy because of something you asked it to do, like an export? And do you need it right now? The answers decide which option fits.

Option 1: quit it

If you are finished with the app, quit it. This is the right choice for anything you opened for a single task and forgot.

Press Command-Q in the app. In Foreman, select it and press End Task, which asks the app to quit the same way, so it can offer to save your work. If it does not quit, Foreman brings it forward, since it may be asking about unsaved changes, and offers Force Quit. An app macOS has marked “Not responding” is force quit at once.

Force quitting loses unsaved changes, so Foreman asks first for an app with windows.

Option 2: freeze it

Sometimes you need the app, but not for a while, and you do not want to close it and lose your place. Suspend freezes it where it is. A suspended app uses no processor time until you choose Resume. The app keeps its place, but nothing happens either: a download stops, a sync stops, a render stops.

In Foreman, right-click the app and choose Suspend…, and Foreman asks you to confirm. A suspended app is marked “Suspended” in its row. Foreman does not offer it for parts of macOS that would freeze the Mac, such as the Finder and the Dock, for Foreman itself, or for processes owned by root, system accounts or other users.

Use this when you want to take the load off for a stretch, and you are happy for the app to do nothing meanwhile. How to pause an app on a Mac instead of quitting it goes through it in detail.

Option 3: slow it down with Efficiency Mode

This fits the awkward middle case: an app you want to keep open and working, but that is taking more than its share of the Mac. A mail app that is always busy, a chat app, a sync tool, a note app that indexes constantly.

When you turn on Efficiency Mode for an app, Foreman does two things while it is in the background:

The app runs at background priority. On Apple silicon that means the efficiency cores, with its disk use turned down.
It is held to about a quarter of the processor time it would take, so it runs in short bursts.

The app keeps working, only more slowly, and the rest of the Mac gets its processor time back.

The important part is what happens when you need the app. While it is in front, or while it is playing sound, it runs at full speed. When you switch away, the slowing returns. So you do not pay for it while you are using the app.

A few more things to know:

It is remembered per app. It applies again the next time the app opens, until you turn it off.
Turn it on: select the app and press the Efficiency Mode button on the toolbar, press Shift-Command-E (⇧⌘E), or right-click and choose Efficiency Mode. The app’s status then reads “Efficiency Mode”, or “Efficiency Mode, paused while in use”.
Turn it off from the toolbar, the right-click menu, the Process menu, the menu bar panel or any page. The app returns to full speed at once.
Menu bar apps and a few parts of macOS get background priority only, without the short bursts.
Who it works for: any process running under your account, which includes many of macOS’s own background processes, such as Media analysis (mediaanalysisd), Photos analysis (photoanalysisd) and iCloud Drive (bird). It is not offered for Foreman itself, for the core parts of macOS (kernel_task, launchd, WindowServer, loginwindow and the like), or for processes owned by root, a system account or another user. The User column shows who owns a process.
Quitting Foreman lets everything go. Slowed apps return to full speed. If Foreman were ever to crash, a separate watchdog lets the slowed apps go.

Be realistic about results. Efficiency Mode works on the app’s processor time and turns its disk use down. How much your Mac improves depends on how busy it is and what else is running, so there is no number to promise. It does not free memory, so if memory pressure is the problem, quitting apps is the fix.

Efficiency Mode on a Mac: how to slow down a background app covers it further.

Which one to pick

Done with it? Quit.
Need it, but not for a while, and fine with it doing nothing? Suspend.
Need it open and working, but it is too greedy? Efficiency Mode.
Not responding? Give it a minute, then force quit.

If the app is busy because you asked it to be, such as a long export, you can also just wait. Efficiency Mode is better kept for the app that is busy for no reason you care about.

When the app keeps coming back

If an app returns to the top of the list every time, look for a cause. Update it first, since fixes for runaway use are common. Check what it is doing, such as syncing a large folder or indexing, and whether it will finish by itself. And check whether it is starting at login: how to stop apps opening at login on a Mac shows how to stop that.

Foreman is free for 24 hours, then $12 once for up to 3 Macs, on macOS 14 Sonoma or later. When the trial ends without a license, Foreman stops reading figures, and anything in Efficiency Mode runs at full speed again.