Mac guides
What your Mac is really doing when it gets hot, loud or slow, and how to fix it. Every fix uses tools built into macOS.
Fix a problem
Step-by-step fixes for the things that make a Mac hot, loud, slow or flat.
- Why are my Mac's fans so loud?Loud Mac fans almost always mean something is keeping the chip busy. Find the app responsible in Activity Monitor and quiet your Mac in a few minutes.
- Why is my Mac so hot?A warm Mac is normal under load. Here's how to tell when it's too hot, the 7 most common causes, and how to cool it down.
- How to check CPU usage on a MacFive ways to see CPU usage on a Mac: Activity Monitor, its Dock icon, floating CPU windows, Terminal, and a menu bar app. Plus what the numbers mean.
- Memory pressure on a Mac, explainedActivity Monitor's memory pressure graph tells you whether your Mac needs more memory. What green, yellow and red mean, and how to fix high memory pressure.
- The spinning beach ball on a MacThe spinning rainbow beach ball means an app has stopped responding. How to wait it out, force quit, and fix a Mac that shows it all the time.
- Why is my Mac's battery draining fast?Find what's draining your MacBook's battery with Activity Monitor's Energy tab and Battery settings, and the fixes that make the biggest difference.
- How to check your Mac's temperaturemacOS doesn't show a temperature reading, but it does track how hot your Mac is. Here's how to check thermal pressure, what's normal, and when to worry.
- Mac slow after an updateA Mac often feels slow for a day after a macOS update while it re-indexes and re-analyses in the background. Here's what's normal, and how to fix it if it stays slow.
- Activity Monitor explainedA plain-English tour of Activity Monitor on Mac: the CPU, Memory, Energy, Disk and Network tabs, what the key numbers mean, and how to quit a stuck app.
Best apps
Roundups where every fact comes from each app's own page.
Busy apps
When one app makes your Mac hot, loud or slow.
- Xcode using high CPUXcode keeps your Mac busy while indexing, building, running previews and simulators. Here's what each one costs and how to make Xcode lighter.
- Docker high CPU on MacDocker Desktop runs your containers in a Linux virtual machine on your Mac. Here's why it uses CPU and memory even when idle, and the settings that make it lighter.
- Zoom making your Mac hotVideo calls are some of the hardest work your Mac does. Here's why Zoom heats up your Mac and the settings that make calls lighter.
- Slack using high CPUSlack is a desktop app built on web technology, so busy workspaces, animations and huddles add up. Here's how to find what's heavy and make Slack lighter on your Mac.
- Microsoft Teams using high CPUTeams meetings and busy chats can keep a Mac working hard. Here's why Microsoft Teams uses so much CPU and memory, and the changes that make the biggest difference.
- Spotify using high CPUSpotify's desktop app should barely register while playing music. If it's using lots of CPU on your Mac, these settings and fixes usually sort it out.
- OneDrive using high CPUOneDrive works hardest when it's syncing lots of files. Here's how to see what it's doing on your Mac, pause it, and keep it from re-syncing busy folders.
- Dropbox using high CPUDropbox uses CPU while it indexes and syncs files. Here's how to check what it's doing on your Mac, pause it, and stop it from re-syncing folders that change all the time.
Puff compared
Honest side-by-sides with apps like Puff.
Mac process glossary
What that process in Activity Monitor is, and why it's using CPU.
- kernel_taskThe core of macOS.
- WindowServerDraws everything on your Mac's screen.
- launchdStarts and manages every process on your Mac.
- logdCollects log messages for macOS.
- syspolicydThe macOS service that checks apps are safe to open (Gatekeeper).
- mds_storesManages your Mac's Spotlight search index.
- All 24 processesThe full glossary, from kernel_task to coreaudiod.