Fix your slow Mac once and for all

We walk you through how to figure out what's slowing down your Mac.

Jason Cipriani
Jason Cipriani
Jason Cipriani Contributing Writer, ZDNet
Jason Cipriani is based out of beautiful Colorado and has been covering mobile technology news and reviewing the latest gadgets for the last six years. His work can also be found on sister site CNET in the How To section, as well as across several more online publications.
Jason Cipriani
5 min read
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It almost never fails, just as you're about to finish a big project for work or school, with a deadline looming, your Mac begins to slow down. The dreaded beachball makes an appearance, spinning countless times all the while you can't get any work done. Eventually, the beachball goes away, and you get some more work done until the ball returns. (Hopefully, Apple's newly announced $6,000 Mac Pro has enough raw power to sidestep this messy business.)

You can either learn to live with the frequent slowdowns, finding some solace in forced miniature breaks, but it's better to take the time to identify what's ailing your MacBook Air or MacBook Pro and fix it -- or at least get it moving again. We walk you through the most common apps that hog up system resources, how to figure out which apps are to blame, and give you the best tips for keeping your Mac running as smooth as possible.

Your browser is (likely) the biggest culprit

Almost any app can hog your Mac's processing power and memory, causing sluggish performance as a result. However, some apps are more prone to bringing your system to a crawl than others. If you use Google Chrome , you likely already know it's usually at the top of the list. As photographer Christopher Michel discovered, Google's Backup and Sync app can also be a drain.


Nobody wants a slow Mac. Nobody.

Sarah Tew/CNET

Image or video editing apps, like iMovie or Photoshop, are also resource-intensive. There's no real getting around that since the computing power required to render large image files or encode video files is taxing on almost all systems.

If you find that Google Chrome is just too burdensome for your Mac, a fact that our review team has found to be the case, you can switch to another browser like Safari or Firefox . Firefox has been working hard on its Quantum-branded version of its browser, with the most recent update improving speed up to 80% for sites like Google, Instagram or Amazon. If you simply can't give up your browser, you may have to adjust how your workflow. Instead of having 15 tabs open at once, limit yourself to seven and learn to be studious in closing older tabs. 

As for image and video editing apps, you can try different apps -- like GIMP -- that are built to run on a wider range of systems with minimal specs, and thus use fewer resources. Keep in mind, but you may sacrifice quality for gaining a little extra performance out of your Mac.

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Before switching up your favorite apps, you'll need to figure out which ones are slowing down your Mac. To do that, you'll need to get familiar with Activity Monitor.

Activity Monitor shows the apps slowing you down

Activity Monitor is built into MacOS and can be found in Applications > Utilities. When you first open Activity Monitor, the CPU tab will be selected. You'll see a list of apps and processes that are running, and every few seconds the list will rearrange. There will be some familiar names and other processes like "WindowServer" that are most likely unfamiliar.

In order to get a clear picture of what's doing what, click on the "% CPU" drop-down to arrange the processes by highest CPU use.

After arranging the processes by the highest CPU percentage, watch it for a few minutes without doing anything on your Mac. Your Mac is constantly carrying out tasks in the background, so the processes will continue to move up and down on the list. Sometimes processes will even jump over 100 percent for a brief moment, before going back to a lower number. Whatever is straining your system should remain near the top of the list at all times.


It's best to view Activity Monitor over several minutes to watch what's taxing your system. 

Screenshot by Jason Cipriani/CNET

For example, I recently watched a "Google Chrome Helper" process sit atop running processes with 20% to 25% of the CPU load. I wasn't really sure what Google Chrome Helper was, but I knew I had multiple processes by that name running. After some research, I discovered it could be a Chrome extension or an open tab. It just so happened that I had about 40 tabs open in Chrome, and so I began closing each tab, one by one until the resource hogging process disappeared from my activity monitor.

What I didn't know at the time is that Chrome has its own Task Manager that looks and works a lot like the Mac's Activity Monitor. To use it, click on the three-dot menu button in Chrome, followed by More Tools Task Manager. A new window will show you everything Chrome is doing on your Mac. Sort either by memory or CPU by clicking on the top of either column. Highlight any running process by clicking on it followed by the End Process button to stop it from running. 

Outside of Chrome's built-in tool, you can use your Mac's Activity Monitor for dealing with rogue app or process after you identify it. You can either troubleshoot like I did, closing each tab, window or app until you figure it out, or you can highlight the process in Activity Monitor and click on the stop sign button with an "X" in it.

You'll see a prompt asking if you want to quit or force quit the process. Start with Quit, and if that doesn't reduce the CPU workload, then click on the same button and select Force Quit.


Even if your Mac is brand-new, you'll still run into apps and programs that can slow it down from time to time. 

Sarah Tew/CNET

Back to the basics

There are going to be times when you open Activity Monitor and find "kernel_task" or "launchd" or even "WindowServer" using up all your Mac's resources. Those processes are pretty vague and have no direct way to link them to a specific app that's running on your Mac.

In those instances, it's a good idea to go back to the obvious troubleshooting tips that we can all overlook at times. They could very well make a difference.

  • Quit all open apps. Don't just close the windows, but right-click on the app icon in the dock and select "Quit."
  • Reboot your Mac completely. Instead of selecting Restart from the Apple menu, select Shut Down and give your Mac a few minutes to completely turn off -- then turn it back on.
  • If you find a specific app always slows down your system, adjust your workflow to use that app without anything else open on your system, and then Quit the app as soon as you're done.

There are other issues that can slow your Mac's performance. Stuff like random login items, running out of hard drive space, or old apps you no longer use can impact performance.

It's a good idea to learn five tips to help you speed up your Mac, and also addressing common Mac issues and how to fix them.

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Published Jun 9, 2019. Update, June 12 at 10 a.m. PT: Added more context.