Mac is slow — 15 causes and how to make it fast again

The five most common causes: 1) too many apps running in the background, 2) the SSD is over 90% full, 3) macOS isn't up to date, 4) Spotlight is indexing (mds_stores), 5) overheating that throttles the CPU. Check Activity Monitor (Cmd+Space → 'Activity Monitor') and sort by %CPU.

After a macOS update, several processes run in the background for hours or days: Spotlight reindexes, Photos analyses images, and iCloud syncs. Wait 24-48 hours. If it's still slow, the new macOS version may simply be too heavy for older hardware — consider a clean install or a RAM/SSD upgrade where possible.

Most likely too many login items. Go to System Settings → General → Login Items and remove anything you don't need at every startup (Slack, Spotify, Dropbox, OneDrive — typical culprits). Restart the Mac afterwards.

Safari slows down from: 1) too many tabs (close the ones you don't use), 2) heavy extensions (Safari → Settings → Extensions), 3) cache corruption (Safari → Clear History and Website Data). If none of that helps, try creating a new user profile and check there.

Chrome is notoriously RAM-hungry. Each tab can use 200-500 MB. On an 8 GB Mac with 20 tabs you're in swap. Solutions: 1) use The Great Suspender or Chrome's built-in Memory Saver, 2) switch to Safari (40% less RAM use), 3) upgrade RAM if possible (only on older Intel models).

Photoshop needs lots of RAM (16 GB+ recommended), a fast SSD, and a Metal-capable GPU. On Apple Silicon, performance is good even at 8 GB. On Intel models with 8 GB, slowness is likely swap. Also check Photoshop's scratch disk in Performance preferences — is it pointing at a full SSD?

Final Cut Pro and 4K editing demand serious hardware. On a MacBook Air, longer 4K renders can lead to thermal throttling (fanless = lower sustained performance). Use optimized media (proxies) while editing, and consider a MacBook Pro 14-inch/16-inch if you edit professionally. A hardware cleaning with us can give 10-20% extra sustained performance.

Stuttering (especially during scrolling and animations) is typically caused by GPU stress or swap. Check Activity Monitor for processes using 100% GPU. If 'Memory Pressure' is yellow or red, you're in swap — close apps or upgrade RAM where possible.

Freezes (the spinning beach ball that won't end) are typically caused by: 1) a hung app stealing system threads, 2) faulty RAM or SSD, 3) corruption in a file system. Force quit (Cmd+Option+Esc). If it keeps happening, run Disk Utility First Aid in Recovery Mode. Constant freezing = hardware, contact us.

If even simple clicks take seconds, either the CPU or the SSD is overloaded. Check Activity Monitor — the 'Disk' tab shows which apps are reading/writing. Spotlight (mds, mds_stores) is a typical culprit on recently indexed folders. Photoanalysisd analyses images in Photos.

First-time launching of an app after startup is always slower than later launches (the cache is empty). If every launch takes 30+ seconds, it's either an old SSD with worn cells, a near-full SSD, or Gatekeeper verifying apps over the network. Check SSD health in Disk Utility.

Finder gets slow from: 1) too many files in a folder (1000+), 2) thumbnails generating for large media files, 3) iCloud Drive syncing. Switch the view to 'List' instead of 'Icons' for fast browsing. If Finder is slow system-wide, it's typically SSD health.

Check Activity Monitor → CPU. Sort by %CPU. Classic culprits: Chrome tabs, mds_stores (Spotlight), photoanalysisd (Photos), kernel_task (thermal throttling — overheating), softwareupdated. Constant 100% with no visible cause = malware or a faulty sensor.

macOS uses nearly all available RAM as cache — that's normal and not a problem. What matters is the 'Memory Pressure' graph: green = OK, yellow = swap is coming, red = active swap (and therefore slowness). If you're consistently in yellow/red, you need more RAM (where possible) or fewer apps.

macOS activates Low Power Mode when the battery drops below 20%. It reduces CPU frequency and dims the screen to extend runtime. That's intentional — plug it into a charger and full performance returns immediately. You can disable Low Power Mode under System Settings → Battery.