Mac uses Activity Monitor instead of Task Manager

Windows computers have Task Manager. Macs have Activity Monitor, which does the same job: it shows you which programs are running, how much memory and processor power each one is using, and lets you force-quit anything that has frozen. The tool is built into every Mac and takes about 10 seconds to open.

Activity Monitor lives in your Applications folder under Utilities. You do not need to read anything or pay for it — it comes with macOS. Once you open it, you will see a list of every process running on your computer, ranked by how much CPU or memory it is using.

Key Takeaways

  • Activity Monitor is the Mac equivalent of Windows Task Manager and shows CPU, memory, and disk usage for every running program.
  • The fastest way to open it is to press Command+Space, type "Activity Monitor", and press Enter.
  • The CPU tab shows which programs are slowing down your processor right now; the Memory tab shows which ones are using the most RAM.
  • You can force-quit a frozen program by selecting it and clicking the X button, which works when a program stops responding to normal commands.

Three ways to open Activity Monitor

Method 1: Spotlight search (fastest). Press Command+Space on your keyboard. A search box will appear in the center of your screen. Type "Activity Monitor" and press Enter. The window opens in about one second.

Method 2: Finder. Open Finder, click Applications in the sidebar, then double-click the Utilities folder. Scroll down until you see Activity Monitor and double-click it. This takes longer but works if you prefer clicking through folders.

Method 3: Launchpad. Click the Launchpad icon in your dock (it looks like a grid of dots), search for "Activity Monitor", and click it. This method is slower than Spotlight but works if you are already in Launchpad.

Understanding the CPU tab

When Activity Monitor opens, you are looking at the CPU tab by default. This shows every process running on your Mac and how much processor power it is using right now. The %CPU column tells you the percentage — a program using 50% means it is taking up half of your processor's capacity.

Programs at the top of the list are using the most CPU. If your Mac feels slow or sluggish, look for a program near the top that you did not start yourself. System processes like kernel_task and WindowServer are normal and should be there. If you see a program you recognize using 80% or more, that is usually what is slowing you down.

The Threads column shows how many separate tasks that program is running at once. Most programs use between 5 and 50 threads. A very high number can mean the program is stuck or misbehaving.

Understanding the Memory tab

Click the Memory tab to see which programs are using the most RAM. The Memory column shows how much RAM each program is using in megabytes (MB) or gigabytes (GB). If your Mac has 8 GB of RAM and one program is using 6 GB, your computer will feel very slow because there is almost no room left for other programs.

The Swap column shows how much data the program has pushed onto your hard drive because there is not enough RAM. Swap is much slower than actual RAM, so a high swap number means your Mac is struggling. If you see large swap numbers, you either need to close some programs or upgrade your RAM.

The Memory Pressure graph at the bottom of the window shows your overall situation in colors: green means you have plenty of RAM available, yellow means you are using most of it, and red means your Mac is out of memory and relying heavily on swap.

Force-quitting a frozen program

If a program stops responding and you cannot close it normally, Activity Monitor can force it to shut down. Find the program in the list, click it once to select it, then click the X button in the top-left corner of the Activity Monitor window. A dialog will ask "Are you sure you want to force quit the process?" Click Force Quit to confirm.

Force-quitting closes the program when ready without saving any unsaved work. You will lose any documents you had open in that program unless you had already saved them. Use this only when a program is truly frozen and will not respond to normal close commands.

After you force-quit a program, you can open it again normally. Force-quitting does not damage your Mac or the program itself — it just stops that one instance of the program from running.

Other useful tabs in Activity Monitor

The Disk tab shows which programs are reading from or writing to your hard drive right now. If your Mac feels slow and the CPU and Memory tabs look normal, check Disk. A program using 100% disk activity can slow everything down even if it is not using much processor power.

The Network tab shows which programs are sending or receiving data over the internet. This is useful if you want to see which programs are using your bandwidth, or if you suspect a program is uploading data without your permission.

The Energy tab (on newer Macs) shows which programs are using the most battery power. This is helpful on a MacBook if you want to see what is draining your battery fastest.

What to do if you find a problem

If you see a program using an unusual amount of CPU, memory, or disk, your first step is to force-quit it and restart it. Many programs have temporary glitches that a restart fixes. If the problem comes back when ready, the program may have a bug or may be incompatible with your version of macOS.

If a system process like kernel_task is using a lot of CPU, your Mac may be overheating, running a background update, or performing disk maintenance. Let it run for a few minutes. If it stays high for more than 10 minutes, restart your Mac.

If you see an unfamiliar process using a lot of resources, search for its name online to find out what it is. Some programs run background processes with names that do not match the program you installed. If you cannot identify a process and it is using significant resources, you can force-quit it to see if anything breaks.

Frequently Asked Questions

Can I close Activity Monitor without closing the programs it shows?

Yes. Activity Monitor is just a viewer — closing it does not affect any of the programs running on your Mac. You can close Activity Monitor and everything will keep running normally. You can reopen it anytime to check on your programs again.

What does "Not Responding" mean next to a program name?

It means the program has frozen and is not answering commands from your Mac. You can try waiting a few seconds, but usually a program marked "Not Responding" needs to be force-quit. Select it and click the X button to close it.

Is it safe to force-quit system processes?

No. Do not force-quit anything that starts with "kernel", "WindowServer", "Finder", or "loginwindow". These are essential to macOS and force-quitting them can cause your Mac to crash or behave unpredictably. Only force-quit programs you installed yourself or recognize as third-party applications.

Why does Activity Monitor show so many processes I did not start?

macOS runs many background processes automatically to handle things like updates, backups, indexing, and system maintenance. Most of these use very little CPU or memory. You can ignore them unless one is using an unusual amount of resources.