[Fixed] WindowServer High CPU and Memory Usage on Mac

Peter Aaron
Last updated: Mar 30, 2022

Summary: We will walk you through what WindowServer on Mac is, why it consumes high CPU and memory resources, and how to reduce its use of CPU and memory.

In the Activity Monitor, you may notice a process named WindowServer that uses a lot of CPU and memory resources. Although we know that high CPU and memory usage can degrade Mac performance, there is no way to completely close the WindowServer process to reduce its CPU and memory usage.

So, what exactly is WindowServer on Mac, and how can you lower its CPU and memory usage? Keep reading!

WindowServer High CPU And Memory Usage on Mac? Here's the Fix

What Is WindowServer on Mac?

WindowServer is one of the core parts of macOS. Simply put, it connects all interface applications and actions to your screen. What you see on your screen is what the WindowServer draws. And every time you launch an app, open a new window, or browser a new page, WindowServer is constantly drawing your screen.

When you launch an application, WindowServer reflects the behavior of that application, and then you can see it on your screen.

Why Does WindowServer Use So Much CPU and Memory on a Mac?

Every program communicates with WindowServer to display things on your screen. Therefore, the more applications you run, the more CPU and memory resources the WindowServer process uses.

WindowServer is designed to help your computer run properly. It does not do anything malicious. Sometimes, however, you may find that WindowServer consumes a lot of CPU and memory resources even though only a few applications are running. The reasons could be:

  • Old Macs with the latest macOS.
  • Too many login items.
  • Unnecessary visual effects.
  • Issues with external accessories.
  • macOS bugs.

How to Check CPU and Memory Usage on Mac

Before knowing how to fix this problem, let's see how to check CPU and memory usage on Mac.

Here are the steps:

  1. Open Activity Monitor via Spotlight or Launchpad.
  2. In the Activity Monitor window, you can see the CPU load, CPU time, and number of threads of the WindowServer process. At the bottom of the Activity Monitor window, you can see your CPU usage.
    Check CPU Usage on Mac
  3. To check your memory usage, click the Memory tab. From the list, you can know which processes are taking up your memory. Below the list, there is a graph showing how much memory space is used.
    Check Memory Usage on Mac

How to Lower WindowServer's CPU and Memory Usage on Mac

Running out of CPU and memory can make your Mac run laggy. Here are some ways to reduce the high CPU and memory usage due to the WindowServer process.

Quit Unused Programs and Apps

As we mentioned earlier, running too many programs or applications can spike CPU and memory. It is a good idea to quit those programs you are not using.

In the Activity Monitor window, highlight the applications and processes you don't use, click the Stop button, and select Quit or Force Quit.

Quit Unused Apps on Mac

By the way, it is also necessary to close windows that are not in use.

Change Display Settings

Effects like motion and transparency can also increase CPU usage. They may be unnecessary for your Mac, especially for older Macs.

Follow the steps below to turn them off:

  1. Click Apple menu > System Preferences > Accessibility.
  2. Click Display in the sidebar and tick Reduce motion and Reduce transparency.
Change Display Settings on Mac

Disable Unwanted Login Items

Login items are programs that start automatically when you log into your Mac. Some of these programs are not necessary to start at startup. Here's how to stop unneeded login items:

  1. Click Apple menu > System Preferences > Users & Groups.
  2. Click the Login Items tab, select the startup item you want to stop, and click the minus (-) button at the bottom of the list.
  3. Unlock the padlock in the lower-left corner to save your settings.
Disable Login Items Mac

Alternatively, you can use BuhoCleaner, a handy startup program manager, to take full control of all the login items and startup services on your Mac. Moreover, its RAM release feature can help you reclaim memory space in seconds. Just click the button below to start.

Free DownloadFor macOS 10.10 and above
100,000+ Satisfied Users Worldwide

Declutter Your Desktop

Apple treats every icon on your desktop as an active window. This means that the more icons on your desktop, the more pressure it puts on your memory.

Organizing your desktop is easy. Just right-click on your desktop and choose Use Stacks, and you'll see all the files on your desktop sorted.

Organize Your Mac Desktop

Optimize Your Mac

Another way you can try is to optimize your Mac. If you don't want to manually deal with the tedious cleanup, you can try BuhoCleaner.

BuhoCleaner is one of the best cleaning and optimization software for Mac. It makes it easy to delete unnecessary files, uninstall unwanted applications, free up memory, monitor CPU load and temperature, etc. Everyone can get started quickly.

Free DownloadFor macOS 10.10 and above
100,000+ Satisfied Users Worldwide
  1. Download, install, and launch BuhoCleaner.
  2. Choose the function in the sidebar and click the Scan button in the right column.
  3. Check the boxes next to the files you want to delete and click the Remove button.
Clean and Optimize Your Mac with BuhoCleaner


Now you have a better understanding of WindowServer on Mac and know what to do when it uses too much CPU and memory resources. Please note that to keep your Mac running properly, you'd better avoid high CPU and memory usage.

Peter Aaron

Peter Aaron is a "crazy" fan of the iPhone. He has been spending years writing helpful tutorials for iPhone users solving tackle iPhone-related issues.