How to Use Task Manager on Mac (Activity Monitor)

Activity Monitor is the Mac equivalent of Windows Task Manager. It shows every app and background process running on your Mac, along with how much CPU, memory, energy, disk, and network each one is using. You can use it to force-quit unresponsive apps, identify what’s slowing down your system, and monitor overall system health. This guide covers everything you need to know, from opening the tool to interpreting its data and troubleshooting common issues.

What You’ll Need

• A Mac running macOS (any recent version, from Catalina to Sonoma and later).
• An administrator account if you need to quit processes belonging to other users or the system itself.

Step-by-Step

1. Open Activity Monitor. The quickest way is to press Command + Space to open Spotlight, type “Activity Monitor,” and press Return. Alternatively, go to Applications → Utilities and double-click Activity Monitor.
2. Understand the tabs. The window has five tabs across the top: CPU, Memory, Energy, Disk, and Network. Each shows a different resource. Start with the CPU tab to see processor usage.
3. Sort processes. Click any column header (like “% CPU” or “Memory”) to sort the list. Click again to reverse the order. Sorting by % CPU or Memory is the fastest way to find the app that’s hogging your system.
4. Identify a process. If you see a process you don’t recognize, click it and then click the “i” (info) button in the toolbar. A window opens with the process’s path, parent process, and more. This helps you determine if it’s a legitimate app or something suspicious.
5. Force quit an app. If an app is unresponsive, select it in the list and click the X button in the toolbar. A confirmation dialog appears—click Force Quit. This is the same as pressing Option + Command + Esc and using the Force Quit window.
6. Monitor overall load. At the bottom of the window, you’ll see a graph and percentages. For CPU, it shows “% User,” “% System,” and “% Idle.” If “% Idle” is consistently low (under 10%), your Mac is working hard.
7. Check memory pressure. Click the Memory tab. At the bottom, look at the Memory Pressure graph. If it’s green, you have enough RAM. Yellow or red means your Mac is swapping memory to the disk, which slows things down.
8. View energy usage. The Energy tab shows “Energy Impact” per app. This is especially useful on laptops—it tells you which apps are draining your battery.
9. Check disk activity. The Disk tab shows how much data each process is reading/writing. High disk activity can slow down the whole system, especially on older Macs with hard drives.
10. Monitor network traffic. The Network tab shows data sent/received per process. This helps identify apps that are uploading or downloading in the background.
11. Use the search box. Type an app’s name in the search field (top-right) to filter the list instantly. This is handy when you have many processes running.
12. Quit a process gracefully. Instead of Force Quit, you can try to quit a process normally. Select it, then go to View → Quit Process (or press Command + Q). This sends a normal quit signal, which allows the app to save its data. Use Force Quit only if the app is truly frozen.

Common Mistakes

• Force quitting system processes. Some processes like kernel_task or WindowServer are essential. Quitting them can crash your Mac or make it unstable. Only quit processes you recognize as apps you opened.
• Misreading CPU percentages. On a Mac with 8 CPU cores, a single app can show up to 800% CPU (each core counts as 100%). Seeing 100% doesn’t mean the app is using the whole computer—it’s using about one core.
• Ignoring memory pressure. People often look at “Memory Used” and panic, but macOS uses as much RAM as possible for caching. The Memory Pressure graph is the real indicator of whether you’re low on RAM.
• Quitting an app from Activity Monitor thinking it will save your work. Force Quit does NOT save unsaved work. It’s a last resort for frozen apps.
• Sorting by the wrong column. If you want to find a memory hog, sort by “Memory” column, not “% CPU.” They often show different apps at the top.

Tips

• Keep Activity Monitor in the Dock. Right-click its Dock icon and select Options → Keep in Dock. Then you can always launch it quickly.
• Show the Dock icon as a live graph. Go to View → Dock Icon and choose what to display (e.g., CPU Usage, Network). This gives you a mini monitor always visible.
• Use the “Window” menu to float on top. If you’re troubleshooting, select Window → Float on Top so Activity Monitor stays above other windows.
• Double-click a process to open the info window with more details, including the executable path and open files/ports.
• Update your apps. If a specific app always uses high CPU, check for updates—developers often fix performance bugs.
• Restart your Mac regularly. If you notice memory pressure is often red, a simple restart clears the RAM and can fix slowdowns.

Troubleshooting

Activity Monitor won’t open. Try restarting your Mac. If it still won’t open, go to Applications → Utilities and double-click it. If that fails, use Spotlight (Cmd+Space) and type the name. If none of that works, your macOS installation may be damaged—run First Aid in Disk Utility.

An app won’t force quit. If the app doesn’t close even after Force Quit, try Command + Option + Escape to bring up the Force Quit window and try from there. If that fails, open Terminal and type killall [appname] (e.g., killall Safari). As a last resort, restart your Mac.

Activity Monitor shows high CPU but you don’t know why. Click the “% CPU” column to sort. Look for processes you recognize. If you see a process like mdworker or mds_stores, that’s Spotlight indexing—it usually settles down after a while. If it persists, you can exclude folders from Spotlight in System Settings → Spotlight.

Memory pressure is always red. This means your Mac is constantly swapping to disk. Close unused apps and browser tabs. If the problem continues, you may need to add more RAM (if possible) or reduce the number of apps you run simultaneously.

You can’t see all processes. By default, Activity Monitor shows only your user’s processes. To see all system processes, go to View → All Processes (or press Command + 2). This includes root processes that run in the background.

Activity Monitor itself is using high CPU. This is usually a temporary spike when you first open it. If it persists, close and reopen it. If it still happens, check for a bug in macOS—update to the latest version.

Frequently Asked Questions

Is Activity Monitor the same as Task Manager?

Yes, functionally it’s the same. Both let you see running processes, monitor resource usage, and force quit apps. The names and layout differ, but the purpose is identical.

How do I force quit an app on Mac without Activity Monitor?

Press Command + Option + Escape to open the Force Quit window. Select the app and click Force Quit. This is the quickest method for a single app.

What does “kernel_task” mean in Activity Monitor?

kernel_task is a system process that manages memory and CPU. It also helps control temperature—if your Mac gets too hot, kernel_task uses more CPU to slow things down. It’s normal to see it, but if it’s using a lot of CPU, your Mac may be overheating.

Why does Activity Monitor show multiple entries for the same app?

Many apps run multiple processes (e.g., Safari has one for the main app, one for each tab, and helper processes). This is normal. You can group them by going to View → Group Processes by App (or press Command + 4).

Can I end a process from Activity Monitor permanently?

No. Ending a process only stops it for the current session. If it’s a background service, it may restart automatically. If it’s an app, it will only relaunch if you open it again. There’s no way to permanently disable a process from Activity Monitor.

Does Activity Monitor show GPU usage?

Yes, in newer macOS versions (Monterey and later), the CPU tab has a GPU column. It shows the percentage of GPU capacity each process is using. This is useful for graphics-intensive tasks like video editing or gaming.

Related

• WhatsApp: How to Block Unknown Numbers
• How to Exit Vi in Linux: A Simple Guide
• iPhone Stuck on Setting Up Apple ID: Fixes