Why is my Mac running slow? 11 causes and 15 fixes (2026)

It doesn’t matter how fast your Mac is when you first set it up — sooner or later, you’ll notice that it is slowing down or lagging. It may happen in every application, or it may affect some more than others. There are many reasons why your Mac might slow down, but by following a step-by-step process, you can eliminate them all one by one to make your Mac run faster.

Why is Mac running slow?

Browsers are getting more memory-demanding. Apps demand a good chunk of your Mac’s memory, which, in the end, is finite. And finally, we are filling our drives to the brim with media files like photos, videos, and other heavy data. So, we’d say that, based on our experience, the math of MacBook running slow is as follows: heavy data and media files (50%), unnecessary apps (30%), and browser data (20%).

How do I find out what is slowing down my Mac?

To diagnose what exactly is causing the issue, first, check how much storage space is left. If your Mac's drive is not full (you have more than 15% of the Mac's drive capacity free), it may be insufficient memory. Go to Activity Monitor to see whether any apps hog it. Enough memory? Check the CPU tab in Activity Monitor. Still no reason? It may be overheating, malware, or a few other causes.

Work through the fixes described below.

How to fix slow MacBook: 11 causes and their fixes

Before diving into fixes, restart your Mac. This is the simplest solution, and it may be all you need to do. Restarting your Mac quits every running app and background process.

If a restart does not help, follow the steps below one by one. None of these fixes requires erasing your Mac.

Note: Although Intel-based Macs are more likely to feel slow and sluggish, Macs with Apple silicon are not immune to it. So, you can use our tips for any MacBook Air, MacBook Pro, or other Mac, regardless of the chip it comes with.

1. Too much running in the background

If your Mac can no longer handle simple tasks and you desire to find answers to the ‘why is my Mac so slow?’ question, Activity Monitor is the place to look once you know your startup disk has enough free space. Your goal is to find the apps using the most memory and CPU and quit the ones you don’t need.

Quick fix: Shut down processes with Activity Monitor

Activity Monitor shows how your Mac’s CPU, memory, and energy are being used. When your Mac is sluggish, use it to find and quit the apps or processes causing trouble. Here’s how to do it:

• Open Activity Monitor. Check out the real-time apps and processes running on your Mac. Pretty complex, agree? But here, you can see what’s causing trouble on your Mac.
• Click the Memory tab, then the Memory column heading at the top of the list — this sorts the programs by the amount of RAM they’re taking up on your Mac. The math is simple: the higher the number, the more memory they use. Then check the Memory Pressure graph at the bottom of the window: green means your Mac is using its RAM efficiently, yellow means it might eventually need more RAM, and red means it needs more RAM.
  

  

• Select one of those heavy-consumer apps or processes, click the Stop button (the “x” icon) in the upper-left corner of the Activity Monitor window, then click Quit. Don’t quit anything you don’t know — it may be a vital system process! For example, do not quit WindowServer, kernel_task, and sysmond, even if they hog CPU; instead, it is safer to quit apps.

How to fix slow Mac in a few clicks

As you’ll see, although easy, the fixes demand some time and effort on your side. But there’s an easier way to speed up your Mac — CleanMyMac and its Smart Care feature. It cleans out system junk and clutter, removes malware threats, updates apps, and optimizes Mac performance. Just open Smart Care in the app and click Scan, then Run, and that’s it. Try CleanMyMac for free.

2. Drive is getting full

Not having enough free space on the startup disk is one of the causes Apple lists for a Mac that runs slowly. So, if there is a chance to lighten the load on your Mac, take it!

Quick fix: Clean up your drive

Sadly, this isn’t as painless as it sounds. Cleaning up old movie files, organizing your Desktop, and searching your Mac for old files is relatively straightforward. However, the hard part comes with cleaning up your entire system and figuring out all the stuff that can be safely removed.

Suppose your iMac or any other Mac model you’ve got is running slow. In that case, one option is to use a utility tool like CleanMyMac. Its innovative technologies clean up your entire Mac, knowing what to clean and where to clean. The app safely removes caches, logs, language packs, and more to help you speed up your Mac.

Here’s how it works:

Once the scan is completed, click the Clean button to remove junk or Review All Junk to check what files will be deleted. All done!

The benefits of using CleanMyMac

• Based on internal data, on average, users find and remove over 9 GB of junk files after the first scan using the Cleanup feature
• Cleans over 50K Macs daily [according to internal data]
• Removes over 81,500 GB of junk every minute [based on internal reports]

Try CleanMyMac for free — see it in action on your MacBook.

3. Mac is overheating

Our Macs manage to handle the most intensive tasks, but they still overheat when too many CPU-heavy processes are active. Other causes of overheating include high ambient temperature, clogged or blocked fans, malware, or frozen or unresponsive apps.

If you notice that your Mac’s getting hotter, first make sure you’re using it where the temperature is between 10° and 35° C (50° and 95° F), on a stable surface with good ventilation, not on a bed or pillow. Then go ahead and try these fixes.

Quick fix: Manage your browser tabs and extensions, check CPU usage & update your Mac

Browser tabs are probably the most resource-intensive processes on your Mac: if they are open, they continuously run and consume RAM and CPU resources. Close all tabs you’re not currently using. Bookmark the pages you need and come back to them later. In Safari, click the Share button > Add Bookmark > Add.

In addition to browser tabs, extensions also consume a lot of CPU as they are running in the background. So, it’s a good idea to check them and disable those you don’t need to avoid Mac overheating. Here’s how to do it for different browsers: 

• Safari: Open Settings > Extensions. Deselect extensions you don’t need or click Uninstall under each extension to remove it. Note: In new macOS versions, you will need to click Open in Finder and then drag an extension to the Trash to delete it.
  

  

  
  
• Chrome: Open menu (three vertical dots icon) > Extensions > Manage Extensions. Toggle off those you don’t need or click Remove to delete them.
  

  

  
  
• Firefox: Open menu (three horizontal lines icon) > Extensions and themes > Extensions. Disable those you don’t need or click ellipsis > Remove to delete them.
  

  

  
  

CPU usage is your main indicator of intensive apps. If your Mac laptop gets warm even when it isn’t doing demanding tasks, Apple suggests checking CPU activity for malfunctioning processes that put a heavy load on the CPU. Use Activity Monitor to see what’s running and what needs to be shut down:

1. Open Activity Monitor (Finder > Applications > Utilities).
2. Click the CPU tab, then click a column heading to sort the list by CPU use. To quit an app you don’t need, follow the steps in fix 1.
   

   

   
   

If you still ask why my MacBook is so slow after completing the chores above, make sure your Mac has all the latest updates. The thing is that new macOS versions (even minor ones) come with bug fixes and are better optimized, meaning that a quick update might be all you need to fix the issue of Mac running slow. More importantly, these updates also include important security patches that may help prevent another cause of MacBook slowdown — malware.

Here’s a quick reminder of how to update macOS:

1. Go to System Settings > General > Software Update.
2. If an update is available, click Update Now or Restart Now to install it.
3. While waiting for the update to download, enable automatic updates.

It is also a good idea to update your apps from App Store > Updates for App Store apps and by using the Check for Updates option in non-App Store apps that offer one. If you are not sure how to update apps on Mac, check out this handy guide.

4. Check your Mac for malware

Did you know that Mac running slow may be one of the tell-tale signs that your device is infected with malware? The thing is that viruses and other malicious apps can run numerous background processes on your Mac. Most commonly, you are not aware of them, but they do consume significant resources, thus slowing your computer down. 

Quick fix: Remove malware from your Mac

The good news, though, is that finding and removing malware is not too complex, although it may be time-consuming. To learn more, check this article on how to remove viruses and malware from Mac. 

Alternatively, scan your Mac for malware using the Protection feature in CleanMyMac. Powered by Moonlock Engine and with a regularly updated database of virus signatures, it can detect and eliminate even the latest macOS-specific threats. 

5. Storage is not optimized

Apple developers have already anticipated the problem with slow-running Macs. Use their helpful recommendations on managing and optimizing your Mac’s storage.

1. Click the Apple menu > System Settings.
2. Here, choose General, then select Storage.
3. In Storage settings, you will see some recommendations on how to optimize storage.

Quick fix: Manage your files and data

If your Mac is running slowly, transfer your files and data to iCloud to save up some space. Just click Store in iCloud. Another helpful tip is to optimize storage on your Mac by removing movies and TV shows you’ve already watched. Finally, always empty the Trash and clean up your folders. All of these can be found in Storage settings. You can also free up space by moving files to an external drive and deleting files you no longer need.

6. Not enough RAM

RAM stands for Random Access Memory. This memory is like fuel for all your apps. So, when you get the “Your system has run out of application memory” message, one solution is to add more RAM, if your Mac’s memory can be upgraded. To check, press and hold the Option key, choose Apple menu > System Information, then click Memory under Hardware. If you see a Memory Slots pane, check Upgradeable Memory there; if you don’t see that pane, your Mac’s memory can’t be upgraded. Or just use this free shortcut.

Quick fix: Flush your RAM using Terminal

You can perform this operation if your system urgently needs a fresh memory. The native macOS tool, Terminal, has a special command to release your available RAM.

• Go to Applications > Utilities > Terminal.
• Now, copy-paste the following command into the Terminal window: sudo purge
• Enter your user password to confirm.
• Enjoy the results!
  

  

Tip

If you started your free CleanMyMac trial in fix 2, you should be able to perform another trick that proved quite effective on most Macs. From our experience, it does boost the performance of many applications.

• Go to your menu bar and click the CleanMyMac Menu icon
• Click Free Up in the Memory monitor

By freeing up memory, CleanMyMac gives your Mac more room to run smoothly, especially when you're juggling a lot of apps or doing something that requires a lot of power.

7. Slow internet connection

Sometimes, it’s not your MacBook that is running slow; instead, your internet connection. For example, a web page could be loading slowly, or a change made in an internet-dependent app would take too long to apply. It may be because of the connectivity issue, not due to a hardware problem.

Quick fix: Audit your internet connection

In this case, the fix is more simple than we thought. Outdated network settings, the distance between your Mac and the Wi-Fi router, or even your network plan can make your Mac software and applications sluggish. Luckily, there are a few ways to deal with these issues.

Try first to fix the internet connection issue with these methods:

• Use an Ethernet cable instead of a wireless connection.
• Move the router closer.
• Reset your Wi-Fi router.
• Close unnecessary tabs.
• Reset Mac Wi-Fi to default.
• Use wireless diagnostics.
• Run a speed test.

8. Too many unused apps

As your Mac may be behaving slowly due to storage issues, it’s good to check whether you have some free space left. Unused apps can take up a lot of space. All of us download applications that seem helpful and exciting at first but turn to clutter up our disks instead of being used frequently.

Quick fix: Uninstall unused apps

Answering the question “why is my iMac so slow?” from our users, the first thing we recommend is getting rid of those dead-weight apps. And here’s how:

1. Open the Finder and navigate to the Go menu.
2. From the drop-down list, select Applications.
   

   

   
   
3. You will see all applications installed on your Mac. Organize the list by size to reveal the largest apps.
   

   

   
   
4. Right-click the app and choose Move to Trash.
   

   

   
   

Mind the fact that if you delete the apps, some leftover files usually stay on your Mac. That’s why it’s a good idea to clean your device from remnants with tools like CleanMyMac. Its Applications feature can also uninstall apps completely, clearing their leftover data.

Quit apps you don’t need to reduce CPU waste. Quit them normally first (press Command-Q) so they can save your changes; use Force Quit only for an app that doesn’t respond:

1. Click the Apple menu and select Force Quit. The Force Quit window opens.

2. All your active apps will be listed in the window that appears.

   

3. Select the app that isn’t responding.

4. Click Force Quit and confirm.

Now, these apps won’t be secretly using your Mac’s power.

9. Turn off unneeded Login Items 

When you turn your Mac on, some apps may also start up at login. These are known as Login Items or startup programs. Needless to say that they can make your Mac sluggish, especially if a lot of such apps run at the same time. Like any other application running on your computer, they consume much-needed resources. Sometimes, you may not even know that they are allowed in the background and launch at login.

Quick fix: Check Login Items

To make your Mac run faster, check Login Items and apps allowed in the background. It can be done within a few clicks. Just follow these steps: 

1. From the main Apple menu, go to System Settings > General. 
2. Now, select Login Items & Extensions. 
3. Check what opens at login and runs in the background and either click the “—” button or turn it off by toggling the switcher. 

But which apps to disable? Consider allowing antimalware software to start up at login. Other apps like browsers, music players, photo editors, or the like just unnecessarily hog your Mac’s resources and increase boot time, so they can be disabled. It is better to open such applications right before you need them and not let them run in the background.

10. Visual overload

Animations and rich graphics are incredibly resource-hungry. And don’t get us wrong, we are not suggesting you switch your Mac back to 1984-style simplicity. But what would you rather have, a slow Mac with high-quality visuals or a fast Mac with good-quality visuals? The choice is yours!

Quick fix: Cut down on animations

Open System Settings > Desktop & Dock.

Disable the following items:

• Magnification
• Animate opening applications
• Automatically hide and show the Dock

Next to “Minimized window animation,” change Genie Effect to Scale Effect. The Scale is a much simpler zoom and less taxing on memory.

11. SMC/NVRAM issues

The final reason for Mac running slow is issues with NVRAM/SMC. Some red flags include random overheating, fans going crazy even if you did not open any resource-intensive apps, or glitches with wake/sleep mode. 

NVRAM (non-volatile RAM) stores vital system information like display settings, speaker volume, time zone settings, etc. SMC (System Management Controller) is responsible for Mac’s important physical aspects: fans, lights, and power. Apple lists symptoms like these among the reasons to reset the SMC.

Quick fix: Reset NVRAM/SMC

On a Mac with Apple silicon, you don’t need the steps below: the NVRAM reset isn’t needed, and the SMC resets when you restart your Mac while it’s plugged into power. For an Intel-based Mac, follow the steps below, depending on what you need to reset (the SMC steps are for Intel Mac laptops without the T2 chip; for other Intel Macs, see Apple’s SMC guide linked below). Apple notes that most Macs don’t need an SMC reset, so try it only if you see the symptoms above.

How to reset NVRAM 

1. Turn off your Mac.
2. Turn on your Mac, then immediately press and hold Option, Command, P and R.

3. Hold the keys for about 20 seconds, during which your Mac might appear to restart.

4. Release the keys.

How to reset SMC

1. Shut down your Mac.
2. On the built-in keyboard, press and hold the left Shift, Control, and Option keys, then also press and hold the power button.
3. Do not release them for 10 seconds.

4. Release all keys, then press the power button to turn on your Mac.

These SMC steps are for Intel-based Mac laptops without the T2 security chip. For other tips, check out this guide from Apple Support on how to reset SMC.

Still slow? Check your apps, disk, and hardware

An app that isn’t compatible with your Mac can slow it down, for example, an app that needs a different processor or graphics card. Check the app’s system requirements and quit any app that doesn’t support your Mac.

Disk problems can slow your Mac, too. First Aid in Disk Utility can check a disk for formatting and directory errors and fix them, though it can’t repair every problem. To check your startup disk, Apple recommends restarting your Mac in macOS Recovery and running First Aid from there.

If these fixes don’t help and you think your Mac may have a hardware issue, run Apple Diagnostics (see the FAQ below) or get service from Apple.

Final thoughts on how to fix Mac running slow

So, we have run over the main methods to speed up a slow Mac. They all boil down to one simple idea — give your Mac some space to breathe. Eventually, any Mac will be filled with garbage that consumes resources, memory, and disk space. Use this article as a guide to speed up your Mac manually, or use an app like CleanMyMac.

Key takeaways

Here is a quick diagnostic tool for you to use:

• Check storage. Low? Free up space.

• Plenty of free storage but still slow? Check Activity Monitor. Are some apps hogging CPU and memory? Quit them.

• Mac running slow at startup? Remove unnecessary login items.
• Slow browser? Close unneeded tabs and check internet connection.
• Still slow? Fix overheating, update macOS and apps, and scan for malware. Then check app compatibility, your disk, and your hardware.