How to use Activity Monitor before pausing apps.

The 60-second Activity Monitor check

Open Activity Monitor with Spotlight: press Command-Space, type Activity Monitor, then press Return. Do not react to the first large number you see. Usage changes from second to second, and a brief spike can simply mean an app is opening a page, indexing a file, decoding video, or completing a task.

1. Watch first: leave the window open for 20 to 30 seconds so you can distinguish a brief spike from sustained activity.
2. Check CPU: click the CPU tab, then sort by % CPU to see what is currently busy.
3. Check Memory: use the Memory Pressure graph as the main signal instead of judging an app by memory alone.
4. Check Energy: compare Energy Impact with 12 hr Power to separate current activity from a longer-running pattern.
5. Add context: ask whether the app is syncing, rendering, downloading, calling, recording, compiling, or installing something important.

The goal is not to make every number zero. It is to find sustained work that you do not currently need, then choose the least disruptive safe action.

How to read the CPU tab

The CPU tab shows how much processor time each process is using. Sort by % CPU, then watch the top of the list for a short period. A process that rises briefly and falls is usually less interesting than an app that remains near the top while you are not using it.

At the bottom of the window, macOS separates CPU time into System, User, and Idle. A low Idle value means the Mac is busy, but it does not by itself tell you that something is wrong. Look at the process name and your current activity before acting. A browser during a video call, a photo editor during export, or a developer tool during a build can legitimately use substantial CPU.

If an ordinary user app stays busy after its task has finished, first check the app itself for a stuck tab, extension, update, or background job. Quit it normally if you are done. If you need to preserve its open windows and the app is otherwise responsive, pausing can be the gentler option.

How to read Memory Pressure

Do not assume that an app using a large amount of memory is automatically a problem. macOS uses available memory to keep apps responsive and can compress memory or reuse cached files. The more useful overview is the Memory Pressure graph at the bottom of the Memory tab.

• Green: memory resources are being used efficiently.
• Yellow: the Mac may eventually need more memory if the current workload continues.
• Red: the Mac needs more memory for the current workload.

Also look at Swap Used and whether pressure remains elevated over time. One snapshot is not enough. If Memory Pressure is green and the Mac feels responsive, there may be nothing to fix even when a browser or creative app occupies several gigabytes. If pressure stays yellow or red, close work you no longer need, reduce heavy tabs or documents, or quit an app normally. Pausing can stop an app's CPU activity, but it is not a substitute for reducing a genuinely memory-heavy workload.

How to read Energy Impact

The Energy tab helps explain battery drain and heat. Energy Impact is a relative measure of current power use, while 12 hr Power summarizes the app's average impact over a longer period. A high current value may be expected during a call or export; a high longer-term value in an app you barely used deserves a closer look.

The same view can show whether an app uses App Nap or prevents sleep. Treat those columns as context, not a verdict: a media app playing audio or a presentation tool may have a legitimate reason to prevent sleep. Before pausing, confirm that the app is not performing work you rely on.

Choose the right action

Never pause a process merely because its name is unfamiliar. AppHalt is intended for user apps you recognize, not macOS services or background processes you do not understand.

What not to pause

Leave an app active whenever interrupting it could lose work, break communication, or leave data incomplete. That includes active uploads and downloads, cloud sync, backups, software installation or updates, file transfers, exports, renders, builds, recordings, screen sharing, presentations, and voice or video calls.

Save documents before pausing, even when the app normally autosaves. If several apps depend on one another—such as a design tool and a sync client—wait until the shared task is complete. When in doubt, leave the app alone or quit it through its normal menu.

Measure again after making a change

Return to Activity Monitor after quitting or pausing an app and observe the same CPU, Memory, and Energy views for another 30 to 60 seconds. Compare a sustained pattern, not a single instant. If the Mac still feels slow or hot, the app you changed may not have been the cause.

For repeatable results, change one thing at a time. This makes it much easier to learn which app, tab, extension, or workflow is responsible—and avoids turning routine troubleshooting into guesswork.

Official Apple references

For the exact fields available in your version of macOS, see Apple's guides to viewing CPU activity, viewing memory usage, and viewing energy consumption. Interface labels can vary slightly between macOS releases.