How to speed up a slow Mac

A Mac that used to feel instant can start to stutter: the spinning wheel shows up, apps take longer to open, and the fans spin more often. Most of the time the cause is something you can fix in a few minutes. Here are 10 fixes that really help a slow Mac, in the order worth trying, plus the tricks that don't.

1. Restart it

If your Mac has been running for weeks, restart it. A restart clears temporary files and swap, ends processes that have slowly grown, and finishes updates that are waiting. It is the cheapest fix on this list.

2. Find out what is slowing it down

Open Activity Monitor (in Applications → Utilities). On the CPU tab, sort by % CPU to find apps working hard in the background. On the Memory tab, look at the Memory Pressure graph at the bottom: green is fine, yellow and red mean your Mac is short of memory. Quit the app responsible, or select a stuck process and click the stop button.

3. Free up disk space

macOS needs free space for virtual memory, caches and updates. When the startup disk is almost full, everything slows down. Keep at least 10 to 15 percent free. Our guide on how to free up space on a Mac covers the safe ways to get there.

4. Trim login items and background apps

Apps that start with your Mac keep running in the background. Open System Settings → General → Login Items & Extensions (just Login Items on older versions). Remove apps you don't need at login, and turn off Allow in the Background for helpers you don't recognise or no longer use.

5. Update macOS and your apps

Updates often fix performance problems and memory leaks. Open System Settings → General → Software Update, and update your apps from the App Store or their own update menus.

6. Tame your browser

Browsers are often the heaviest app on a Mac. Close tabs you don't need, remove extensions you don't use, and keep the browser up to date. If one site keeps the fans spinning, check the browser's own task manager to find it.

7. Reduce visual effects on older Macs

On older Macs, transparency and animations cost graphics power. Open System Settings → Accessibility → Display and turn on Reduce motion and Reduce transparency.

8. Let Spotlight finish, or rebuild a stuck index

After an update or a big file copy, Spotlight re-indexes your disk and uses CPU for a while. That is normal. If indexing never seems to finish, or search results are wrong, rebuilding the index helps: run sudo mdutil -E / in Terminal. Our Optimize tools can do this with one click.

9. Remove broken background helpers

Apps you uninstalled by dragging them to the Trash can leave launch agents behind that try to start at every login. Look in ~/Library/LaunchAgents for files named after apps you no longer have. Roomy's Optimize screen lists launch agents and flags the broken ones.

10. Free up memory, if you really need to

macOS manages memory well on its own, and free memory isn't a goal in itself. If one app needs a lot of memory right now, quitting other apps helps more than any cleaner. Running sudo purge in Terminal releases inactive memory, and Roomy's Free up memory does the same, but the effect is temporary.

What doesn't help

• "RAM cleaners" that run all the time. They use memory and CPU themselves.
• Deleting system files. It can break macOS and won't make it faster.
• Clearing caches every day. Apps rebuild them, so a fresh cache makes them slower for a while.

When it is the hardware

If your Mac is short of memory for the apps you run every day, or very old, software fixes only go so far. Heavy fan noise and slowdowns under load can also mean dust and heat. Check Memory Pressure over a normal day before deciding.

Frequently asked questions