Your Mac is slow: find out why and speed it up

Why it happens

A Mac usually slows down for a handful of reasons: too many apps or browser tabs open, not enough free memory or disk space, one app stuck working too hard, or weeks without a restart. Right after a macOS update it can also be busy re-indexing in the background. Each of these has a quick check.

How to fix it

1. Save your work, open the Apple menu and choose Restart. This clears memory and stops anything stuck in the background.

2. After it restarts, open only what you need. Quit other apps with Command-Q; a small dot under an icon in the Dock usually means that app is still running.

3. Press Command-Space, type Activity Monitor and press Return. Click CPU, then the % CPU column heading. The app at the top is the one working hardest. Quit it if you don't need it, or restart it if you do.

   Activity Monitor›CPU

4. Click Memory and look at the Memory Pressure graph at the bottom. If it's yellow or red, close apps and browser tabs until it turns green.

   Activity Monitor›Memory

5. Check your free space in System Settings > General > Storage. A nearly full drive slows everything down, so free some room if it's tight.

   General›Storage

Still not fixed?

1. Just updated? Spotlight and Photos re-scan your files for a day or two. Leave the Mac plugged in and awake, then judge the speed again.

2. Remove apps that start by themselves under Open at Login. Each one takes memory from the moment you log in.

   General›Login Items & Extensions›Open at Login

3. Install the latest macOS update and app updates in General > Software Update. Fixes for slowdowns often arrive that way.

   General›Software Update

4. Start in Safe Mode and use the Mac for a few minutes. If it's quick there, something that loads at login is to blame. Restart normally and remove it.

5. Run First Aid in Disk Utility. If it finds errors it can't repair, or the Mac is still slow with nothing running, contact Apple Support or a repair shop: the drive or another part may have a hardware problem.

   Disk Utility›First Aid