How to use Activity Monitor on a Mac

howtosimply.com/guides/how-to-use-activity-monitor-on-a-mac/ · Checked October 2026 · MacBook Neo · macOS 27.0.1

7 of 7 steps with real screenshots · 3 official sources below

Device

Mac

Shown on

macOS 27.0.1 (MacBook Neo)

App

Activity Monitor

Real screenshots

7 of 7 steps

Checked

October 2026

Sources

3 official, linked below

Step by step

1. 

   Open Activity Monitor

   Press Command + Space, type Activity Monitor and press Return. The app is in Applications, Utilities. On our MacBook Neo it opened on My Processes, shown under the window title.

   Done

2. 

   Look at the CPU tab

   Click CPU in the toolbar, then click the % CPU column to put the busiest process at the top. An app that stays high when you are not using it may be stuck. On our MacBook Neo, with the list sorted by % CPU, kernel_task was at the top.

   Done

3. 

   Look at the Memory tab

   The Memory Pressure graph at the bottom shows how hard the Mac is working its memory. Green is fine. Apple reads it this way: yellow, the Mac might eventually need more memory; red, it needs more memory. Closing apps and browser tabs lowers the pressure. On our MacBook Neo, with 8 GB, the graph was yellow, with 6,97 GB Memory Used and 2,75 GB Swap Used.

   Done

4. 

   Look at the Energy tab

   On a MacBook, Energy Impact and the 12 hr Power column show how much battery each app has used. Our MacBook Neo's Energy tab, set to Applications in Last 12 Hours, also showed an App Nap column and a Battery (Last 12 hours) graph.

   Done

5. 

   Look at Disk and Network

   They show how much each process reads, writes, sends and receives. This is where you see what is busy when the Mac seems to work by itself. On our MacBook Neo the Disk tab lists Bytes Written and Bytes Read per process, with Data read and Data written totals at the bottom. The Network tab, in the step 6 picture, lists Sent Bytes (cut to Sent Byt… on our screen), Rcvd Bytes, Sent Packets and Rcvd Packets.

   Done

6. 

   Find a process

   Type a name in the Search field at the top right. The View menu switches between All Processes, My Processes, Windowed Processes and other groups. The line under the window title names the view: on our MacBook Neo it read My Processes when the app opened (step 1), Applications in Last 12 Hours on the Energy tab (step 4) and All Processes in this picture.

   Done

7. 

   Quit a hung app

   Select the process and click the stop button, the X in a circle, at the left of the toolbar. Choose Quit first. Use Force Quit only if that does not work: unsaved changes are lost. On our MacBook Neo, with Calculator selected, the stop button asked: Do you really want to quit "Calculator"? with Quit, Force Quit and Cancel.

   Done

If you do not see this option

• Some tabs are not shown On our MacBook Neo all five tabs, CPU, Memory, Energy, Disk and Network, sit in the toolbar. Make the window wider if some are cut off. Source: View information about Mac processes in Activity Monitor
• The stop button does nothing It acts on the selected process. Click a row first: on our MacBook Neo the button was dim while no process was selected. Source: View information about Mac processes in Activity Monitor

If this does not work

• An app will not quit Choose Force Quit in the dialog, or choose Force Quit from the Apple menu. Source: How to force an app to quit on your Mac
• The Mac is slow but no app is high Check the Memory tab. Our MacBook Neo with 8 GB was using 2,75 GB of swap. Close apps and browser tabs you do not need. Source: If your Mac runs slowly

About this guide

Activity Monitor is the Mac's counterpart to the Windows Task Manager. It answers three questions: which app is keeping the processor busy, which one is using memory, and what is draining the battery.

Screenshots: MacBook Neo, macOS 27.0.1, dark mode.

Good to know

Leave alone anything you do not recognise that belongs to the user root or to the system, such as kernel_task or WindowServer. They are parts of macOS.

Double-click a process to see details about it.

A quicker way to end one frozen app: how to force quit a frozen app on a Mac.

What to do with what you find: Mac running slow: 8 fixes to try and MacBook getting hot: 7 things to check.

In short: Open Activity Monitor, sort by % CPU, check Memory Pressure, Energy on a MacBook, search for a process, stop button to quit a hung app.