How to Fix WindowServer High CPU Usage on Your Mac

Is your Mac feeling sluggish, with simple actions like clicking between windows or scrolling seeming to lag? One common culprit is the WindowServer process consuming an unusually high percentage of your Mac‘s CPU resources.

WindowServer is a core part of macOS responsible for rendering all the graphical elements you interact with – application windows, menus, buttons, animations, and more. When it starts consuming excessive CPU power, you‘ll definitely feel the impact on performance.

But don‘t worry! There are several troubleshooting steps you can take to get WindowServer‘s CPU usage back under control and have your Mac feeling snappy again. In this guide, we‘ll walk through the most effective fixes step-by-step.

Understanding WindowServer‘s Role

First, it‘s helpful to understand a bit more about what the WindowServer process actually does. In a nutshell, it handles the display of all graphical elements in macOS. This includes:

• Drawing application windows and their contents
• Rendering menus, buttons, sliders and other UI elements
• Animating things like window minimizing/maximizing, Mission Control, etc.
• Handling transparencies and blur effects
• Receiving input events from the mouse, keyboard and trackpad

Whenever you do anything that changes what‘s shown on screen, WindowServer jumps into action to update the display. As you can imagine, the more windows and graphical elements there are to manage, the harder WindowServer has to work.

Why WindowServer‘s CPU Usage Gets High

Under normal conditions, WindowServer‘s CPU usage will fluctuate a bit as you use your Mac but should remain relatively low. However, there are a variety of issues that can cause it to consume more CPU power than it should:

Too many open apps and windows: The more applications and windows you have open, the more graphical elements WindowServer has to render and keep track of. Especially if you have a lot of browser tabs or complex apps open, this can add up.

Buggy or leaked application memory: Poorly coded applications can develop memory leaks or have other bugs that place excessive strain on the graphics rendering system. This can cause WindowServer to work overtime.

Outdated software: Older versions of macOS or applications may have inefficient graphical rendering that taxes WindowServer more than newer optimized versions. It‘s important to keep everything updated.

Transparency & animations: macOS includes many attractive visual effects like transparent menu bars and animated transitions. While nice to look at, these do increase the load on the graphics rendering system.

Display features: Native macOS features like Night Shift (which adjusts display color temperature) and ProMotion (which enables high refresh rates on some Macs) can increase WindowServer overhead when active.

Multiple displays: If you have multiple external displays connected, or if you heavily use macOS virtual desktops (Spaces), WindowServer has to render even more content which can lead to high CPU usage.

Desktop clutter: Every icon, widget or other item stored on your desktop requires resources for WindowServer to draw. A desktop with hundreds of items will take more work to render than a clean, minimal desktop.

If your Mac is suffering from one or a combination of these issues, it can overload the WindowServer process and slow things to a crawl. Fortunately, it‘s usually not too difficult to pin down the cause and implement a fix.

Step-by-Step Fixes for High WindowServer CPU Usage

Follow these troubleshooting steps in order until you identify the issue and get WindowServer‘s CPU usage under control:

1. Close Unnecessary Applications & Windows

Start by shutting down any applications you aren‘t actively using. Within the apps you are using, also close any windows or tabs that aren‘t strictly necessary. Reducing the number of items WindowServer has to manage can have a big impact.

To close an app completely, right-click its icon in the Dock and select Quit. Alternatively, use keyboard shortcuts – ⌘+Q quits an application. You can also press ⌘+H to momentarily hide an app.

For Macs with Apple silicon, you no longer need to fully quit apps in many cases. But on Intel-powered Macs or if an app seems to be misbehaving even in the background, it‘s best to fully close it.

2. Restart Your Mac

If you‘ve closed unnecessary apps and windows but WindowServer is still chugging away, a simple restart is the next step. Restarting can clear out temporary system glitches or leaked memory issues that could be plaguing WindowServer.

To restart your Mac, click the Apple menu and select Restart. If your Mac isn‘t responding, you may have to hold the power button to force a restart. Don‘t do this regularly though, as it can risk data loss or corruption.

Upon restart, check WindowServer‘s CPU usage in Activity Monitor. If it has dropped back to low levels, you‘re all set. If it quickly climbs again, move on to the next steps.

3. Update macOS & Applications

Using an outdated version of macOS is a common cause of performance issues, including high WindowServer CPU usage. Apple includes optimizations and bug fixes in each macOS update that can help keep WindowServer running smoothly.

To check for macOS updates, click the Apple menu and select System Settings (or System Preferences on older macOS versions). Click Software Update in the sidebar. If any updates are found, click Update Now.

Don‘t neglect your applications either – keeping your apps updated will minimize glitches that could cause them to tax WindowServer. Check each app‘s built-in update feature, or for apps downloaded from the App Store, update them using the App Store app.

4. Reduce Transparency & Motion Effects

While the transparent menu bar, Dock, and animated effects like Mission Control look great, they do require extra horsepower from WindowServer. Turning them off is an easy way to lighten the load.

Open System Settings and navigate to Accessibility in the sidebar. Scroll down and check "Reduce motion" and "Reduce transparency". Your Mac‘s interface will change to a simpler look which is faster to render.

You can also tone down the macOS eye candy in an app like iStat Menus. Its "Effects" section allows choosing "Reduced" for transparency and motion independently from the global Accessibility settings – great for fine-tuning.

5. Disable Night Shift & ProMotion

Night Shift automatically reduces blue light from your display in the evenings for more comfortable viewing. ProMotion refers to the high refresh rate (up to 120hz) offered on high-end Macs. Both features can slightly increase WindowServer overhead.

To disable Night Shift, go to Display in System Settings. In the Night Shift section, uncheck "Turn on until tomorrow". To disable it permanently, also uncheck "Schedule".

ProMotion is only adjustable on external displays. If you have one connected, go to Display in System Settings, select the display, and change the Refresh Rate to 60hz.

6. Clean Up Your Desktop

Every file, folder and widget on your desktop requires resources from WindowServer to render. If your desktop is cluttered with hundreds of icons, that can add up.

Take some time to delete old files and move current ones to an appropriate folder in your Home directory. Pare your desktop down to just the bare essential shortcuts and widgets you need. Even moving files to subfolders on the desktop can help.

7. Adjust Multi-Display & Mission Control Settings

For multi-display Mac setups, macOS creates a separate "Space" for each display by default. This increases WindowServer load, as it has to maintain independent desktops for each screen.

If you don‘t need this feature, go to Mission Control in System Settings and uncheck "Displays have separate Spaces". Now all your displays will combine into one continuous desktop, lessening the load on WindowServer.

While in Mission Control settings, also uncheck "Automatically rearrange Spaces based on most recent use". This will prevent macOS from shifting around your desktops, which requires WindowServer to re-render everything.

Advanced Troubleshooting

If you‘ve followed all the above steps and WindowServer is still consuming high CPU, you may have a deeper issue at play – like a misbehaving application or system component. Here are a few additional steps to try:

• Use Activity Monitor to identify apps using high CPU or memory. If an app appears to be using excessive resources, try updating it, or contact the developer for assistance.

• Boot in Safe Mode (hold Shift while booting) and see if the issue persists. If WindowServer behaves in Safe Mode, it points to an issue with third-party apps or login items.

• Create a new user account and log in to it. Check if WindowServer CPU usage is still high. If not, there may be a problem with your primary user account.

• Consider backing up your data and reinstalling macOS. This is a big step but can resolve tricky system issues. Restore your data but don‘t migrate applications – just re-download them so you have clean installs.

Wrapping Up

High WindowServer CPU usage is frustrating but fixable. Start by reducing load – close apps, update software, turn off enhancements. If the issue persists, dig deeper with Safe Mode, new user accounts, or a fresh macOS install.

Implementing these fixes will not only reduce WindowServer CPU load but make your entire Mac faster and more stable. And remember, you can always re-enable features like transparency once you‘ve got WindowServer tamed.

Mac troubleshooting can feel daunting, but armed with the right knowledge, you can resolve most issues yourself. Always start simple, then get progressively more complex until you find a solution. With a cool-running WindowServer, your Mac will be back to its best in no time.