Mac running slow? 8 fixes to try

2 min read · 8 steps · Updated 2 October 2026

Short answer

Restart the Mac, check Activity Monitor for an app using too much memory or processor, free up storage until at least 10% of the disk is empty, and remove apps that open at login. Then install any macOS update.

A slow Mac is usually short of memory or storage, or has one app misbehaving in the background. The Mac has a built-in tool that shows which.

Step by step

  1. Restart

    Click the Apple menu and choose Restart. If you normally only close the lid, the Mac may have been running for weeks.

  2. Find the app that is using everything

    Open Activity Monitor from Applications, Utilities, or press Command + Space and type its name. On the CPU tab, click the % CPU column to sort. An app that stays near the top at a high percentage is the cause. Select it and click the X button to quit it.

  3. Look at Memory Pressure

    On the Memory tab, the graph at the bottom should be green. Yellow or red means too many apps and browser tabs are open. Close some.

  4. Free up storage

    A nearly full disk slows macOS badly. Our guide: how to check and free up storage on a Mac.

  5. Trim login items

    Fewer apps starting by themselves means more memory for your work: how to stop apps opening at login.

  6. Close browser tabs and remove extensions

    Each tab is a small app. Dozens of tabs and several extensions can use more memory than everything else together.

  7. Update macOS and your apps

    Open System Settings, General, Software Update. Update apps in the App Store under Updates.

  8. Give it time after an update

    After a big macOS update, the Mac re-indexes files for search and Photos for a few hours. It is slow and warm during that time and recovers by itself when left on and plugged in.

Good to know

If the fans are loud and the Mac is hot, check that the vents are not blocked and that it is not sitting on a blanket.

You do not need a "cleaner" app. Many are aggressive adverts, and some are malware.

An older Mac with a mechanical hard disk and 8 GB of memory or less will stay slow with current software whatever you do.

In short: Restart, check Activity Monitor, free storage, trim login items, update.

Sources
  • Apple Support: If your Mac runs slowly

Rules and prices change. Check the official source before you act.