Mac maintenance
25 Things to Try When Your Mac Is Slow (in Order of Effort)
25 fixes for a slow Mac, ordered from zero-effort restarts to deep cleanup. Real menu paths, real numbers, no fluff. Sonoma and Sequoia.
Your Mac was fine three months ago. Now Safari takes four seconds to launch, the spinning beachball shows up during plain text editing, and Mission Control stutters. Before you book a Genius Bar appointment, work this list top-to-bottom — the early items take 30 seconds and fix maybe 60% of slow Macs.
The 30-second fixes (try these first)
1. Restart it. Apple menu, Restart, uncheck “Reopen windows when logging back in.” Macs stay awake for weeks at a time. Memory pressure builds up, kernel extensions misbehave, the WindowServer process gets bloated. A clean restart solves more problems than any tip below.
2. Close every browser tab. Open Activity Monitor (Applications, Utilities, Activity Monitor), sort by Memory. If “Google Chrome Helper (Renderer)” is taking 2 GB+, that’s your problem. Cmd-Q the browser, reopen with one tab.
3. Quit apps you forgot were open. The dot under the app icon in the Dock means it’s running. Right-click each one, Quit. People leave Photoshop, Slack, and three Finder windows open for weeks.
4. Free up startup disk space. Apple menu, About This Mac, More Info, Storage Settings. If you’re under 10% free space, macOS performance falls off a cliff. Anything under 20 GB on a 256 GB drive will cause stuttering.
5. Disable login items. System Settings, General, Login Items & Extensions. Look at the top list — anything you don’t recognize, toggle off. Spotify, Adobe, Microsoft, Dropbox, all auto-launch.
There’s a faster waySweep does most of this list automatically. Try Sweep free →
The five-minute fixes
6. Empty the Trash. Finder, right-click Trash, Empty Trash. Files in Trash still count against your storage. Some people have 80 GB sitting there.
7. Empty browser caches. Safari, Settings, Advanced, check “Show features for web developers.” Then Develop menu, Empty Caches. For Chrome: Settings, Privacy and security, Delete browsing data, choose “All time,” tick Cached images.
8. Check Mail. Open Mail, hit Cmd-, and look at the Accounts tab. The Mail database (~/Library/Mail) regularly grows past 30 GB. Mailboxes menu, Erase Junk Mail, then Erase Deleted Items.
9. Clear Downloads. Finder, Cmd-Shift-D for Downloads. Sort by size. The 6 GB installer .dmg from 2023? Gone. The 4K screen recording? Gone if you’ve already shared it.
10. Restart Spotlight indexing if it’s stuck. System Settings, Siri & Spotlight, Spotlight Privacy, drag your hard drive in, OK, then remove it. Forces a reindex. Check Activity Monitor — if mds_stores is hammering CPU for over an hour straight, this is the fix.
The 15-minute fixes
11. Update macOS. System Settings, General, Software Update. 14.5 to 14.6 fixed real performance bugs. Same with the Sequoia 15.x point releases.
12. Update apps. App Store, Updates tab. For non-App Store apps, check Sparkle-style updaters in each app’s menu.
13. Run First Aid on the disk. Disk Utility, select Macintosh HD, First Aid. Catches B-tree corruption that silently slows reads.
14. Check Activity Monitor’s Energy tab. Sort by 12-hour average. Anything above 5.0 with the lid closed is misbehaving — usually Photos doing facial recognition, or a Chrome tab playing video in the background.
15. Reset NVRAM (Intel only). Cmd-Option-P-R held during boot. Apple silicon Macs reset NVRAM automatically and don’t need this.
16. Look at Storage Recommendations. System Settings, General, Storage. The colored bar shows what’s eating space. “Other” is often Mail attachments and old iOS backups in ~/Library/Application Support/MobileSync/Backup/. A single old iPhone backup can be 80 GB.
~/Library/Developer/Xcode/DerivedData folder, which can balloon to 60 GB on a developer's machine.The deeper fixes
17. Uninstall apps you haven’t used in 6 months. Launchpad, hold Option, click the X — except that only works on App Store apps. For everything else, dragging the app to Trash leaves behind 100s of MB in ~/Library/Application Support/, ~/Library/Caches/, and ~/Library/Preferences/. Use a real uninstaller.
18. Audit menu bar apps. That little row of icons next to Wi-Fi? Each one is a daemon. Cleanshot, Bartender, Magnet, Rectangle, Notion, Loom, BetterTouchTool — they’re all running constantly.
19. Check kernel_task. Activity Monitor, CPU tab. If kernel_task is at 200%+ CPU, your Mac is throttling for thermal reasons. Get a vacuum to the vents, or check if you’re running on a hot surface like a comforter.
20. Audit Safari extensions. Safari, Settings, Extensions. Disable everything, restart Safari, see if it’s faster. Add back what you actually use.
21. Reset Safari completely. ~/Library/Safari has the bookmarks; ~/Library/Caches/com.apple.Safari has the temp data. The cache can hit 8 GB.
The nuclear options
22. Boot into Safe Mode. Apple silicon: shut down, hold power until “Loading startup options,” select your disk, hold Shift, click “Continue in Safe Mode.” Intel: hold Shift during boot. Safe Mode disables all third-party kernel extensions and login items. If it’s fast in Safe Mode, you’ve got a third-party app problem.
23. Reinstall macOS over the top. Apple silicon: shut down, hold power, Options, Reinstall macOS. Doesn’t touch your data — just reinstalls the OS files. Takes about an hour. Solves a surprising amount.
24. Erase All Content and Settings. System Settings, General, Transfer or Reset, Erase All Content and Settings. Like Erase iPhone — wipes the user data, keeps macOS clean. Then restore from Time Machine or set up fresh.
25. Replace the SSD’s free space. SSDs slow down when they get past 80% full because TRIM has nowhere to write new data. If you’re consistently above 80%, the only fix is sustained cleanup. This is exactly the thing maintenance apps automate.
How long should each step take?
A clean Sonoma install on an M2 with 16 GB RAM should:
- Boot in under 25 seconds
- Open Safari in under 1.5 seconds
- Open Mail in under 3 seconds
- Open Finder in under 1 second
- Run Mission Control without dropping frames
If you’re meaningfully slower than this after working through the list, the problem is hardware — most often a failing SSD, a hung kernel extension, or a battery so degraded it’s throttling the CPU. System Settings, General, About, System Report, Power, will tell you the battery cycle count and condition. Anything labeled “Service Recommended” is throttling.
The first 10 items on this list fix the majority of slow Macs. The next 10 catch most of the rest. The nuclear options are for the cases where something is genuinely broken and a clean slate is faster than diagnosis.