Why Is My Mac So Slow? 10 Things to Check

A Mac usually feels slow for one of four reasons: one app is using most of the processor, memory is under pressure, the startup disk is nearly full, or too many things start at login. Activity Monitor and System Settings will show you which one it is. Work through the ten checks below in order and stop when the problem is found. None of them needs extra software.

Find what is busy

1. Restart the Mac

Choose the Apple menu, then Restart. A restart closes stuck processes and clears temporary files. If the Mac has been running for weeks, try this first.

2. Check the processor in Activity Monitor

1. Open Activity Monitor from Applications, then Utilities.
2. Click the CPU tab, then the % CPU column to sort the busiest process to the top.
3. If an app you recognise stays at the top for minutes while you are not using it, quit it and open it again.

3. Check memory pressure

In Activity Monitor, click the Memory tab and look at the Memory Pressure graph at the bottom. Green is fine. Yellow or red means the Mac is short of memory, so close apps and browser tabs you are not using.

4. Wait for indexing after an update

After a macOS update or a large file copy, Spotlight rebuilds its index. Processes named mds and mdworker appear near the top of the CPU list while this happens. It finishes on its own, so leave the Mac plugged in and give it time.

Check the disk

5. See how much space is free

Open System Settings, then General, then Storage. macOS needs free space for temporary files and for swap when memory is short, so a disk that is almost full can make everything feel sluggish. If only a few gigabytes are free, clear some space. Our guide to freeing up Mac storage has the steps.

6. Empty the Trash

Files in the Trash still take up space. Choose Finder, then Empty Trash.

Reduce what runs in the background

7. Trim login items

1. Open System Settings, then General, then Login Items. On newer versions of macOS it is named Login Items & Extensions.
2. Under Open at Login, select anything you do not need at startup and click the minus button.
3. Under the background items list, switch off helpers for apps you no longer use.

8. Tidy the browser

Each open tab and each extension uses memory. Close tabs you are finished with and remove extensions you do not use. In Safari, extensions are under Safari, then Settings, then Extensions.

Check the settings

9. Update macOS and your apps

Open System Settings, then General, then Software Update. Then open the App Store and click Updates. Updates often include fixes for bugs that waste processor time or memory.

10. Look at Low Power Mode and visual effects

Low Power Mode saves energy by reducing performance. Check it under System Settings, then Battery. On an older Mac you can also open Accessibility, then Display, and turn on Reduce motion and Reduce transparency to lighten the load on the graphics hardware.

What MacPrune does about it

MacPrune makes no promise about speed. It helps with two of the checks above. The Monitor page shows live CPU, GPU, memory, disk, network and battery, along with the apps using the most CPU and memory, and you can quit them from there. The menu bar has a Mac Health panel with storage, memory, battery, CPU and network at a glance.

If the disk is the problem, the Clean page scans once and groups what it finds into Safe to clean, Review before cleaning and Handle with care. What you choose is moved to the Trash after a confirmation, and the space is freed when the Trash is emptied.

If it is still slow

If the Mac is hot or the fans are loud as well, read how to fix loud Mac fan noise and what to do when a Mac overheats. If nothing here helps, the cause may be hardware, and Apple Support can run diagnostics. To check your disk and running apps in one place, download MacPrune. The basic version is free.