How to quit an app that is using too much CPU
Open Activity Monitor, select the app or process, click the Stop button in the upper left corner, and choose Quit. Choose Force Quit only if Quit does not work. Apple says Quit is the safe choice, because it only quits when doing so will not cause data loss.
Steps
- Open Activity Monitor.
- Select the app or process in the Process Name list. Apple says an unresponsive process is marked “(Not Responding)” and appears red.
- Click the Stop button in the upper left corner of the window.
- Choose Quit or Force Quit.
Quit or Force Quit
- Quit works like choosing File then Quit inside the app. The process quits only when it is safe, so it will not quit if that could cause data loss or interfere with another app.
- Force Quit quits the process immediately. Apple warns that open files may lose data, and other apps or processes that use it could have problems.
Try Quit first. Give it a short wait, because an app that is saving can take a moment. Use Force Quit when an app has stopped responding.
Find the right one
Type the name in the search field, or sort the list by clicking a column heading such as CPU. To check whether another process depends on the one you are about to quit, choose View > All Processes, Hierarchically.
Processes you do not own
Apple says that if you try to quit a process you do not own, you may need to authenticate as an administrator. Do not quit a macOS system process unless you know what it does. If you are unsure, restart the Mac instead.
Why it was busy
Before you quit, note whether the CPU use was normal for the work you were doing. A video export keeps the processor busy and is not a fault. See how to check CPU and memory use. If battery is the concern, the energy tip helps you sort by impact.
NotchStar’s gauges
NotchStar’s System tool shows CPU and memory totals, so a ring that stays orange or red tells you to open Activity Monitor. It does not list or quit processes. It shows totals only, so the quitting itself happens in Activity Monitor.
