Mac slow after an update: how to fix it

Step-by-step guide to restore performance after installing a new macOS version

Is your Mac running slower after updating macOS? You’re not alone. While updates offer new features, they can also cause performance issues—especially on older devices. Here’s what you can do to get your Mac running smoothly again.

🔍 1. Wait 24–48 hours: it’s normal at first

Right after an update, macOS performs background tasks:

• Spotlight reindexing

• iCloud syncing

• System adjustments

  
  

Tip: Let your Mac run for a day or two before panicking. Keep it plugged in and connected to Wi-Fi.

🧹 2. Check activity monitor

Find out which apps are using too many resources:

• Go to Applications > Utilities > Activity Monitor

• Sort by “% CPU” or “Memory”

• Quit any unnecessary or unresponsive apps

  
  

Older apps might not be optimized for the new system and cause lag.

🧼 3. Free up disk space

macOS updates take up storage. A full drive slows everything down.

• Delete large or duplicate files

• Use apps like CleanMyMac or DaisyDisk

• Clear cache, old downloads, and temp files

  
  

Try to keep at least 10–15% of your disk space free.

🛠 4. Reset NVRAM and SMC

These store low-level settings that may get scrambled during updates.

Reset NVRAM:

1. Shut down your Mac

2. Turn it on and press Option + Command + P + R for 20 seconds

   
   

Reset SMC:

It depends on your Mac model. For Intel Macs, there are specific key combinations (check support.apple.com).

🧠 Conclusion

A slow Mac after an update doesn’t mean it’s time for a new one. These fixes can bring your device back to life. At iProX, we believe in making your Apple devices last longer—with smart, sustainable solutions.