Restart your Mac
Update macOS and all apps
Check Activity Monitor for CPU, Memory, Disk, and Network spikes
Quit unused apps and tabs
Close background apps and browser extensions you don’t need
Remove login items you don’t use: System Settings → General → Login Items
Disable unnecessary startup services: System Settings → General → Login Items (and related options)
Free up storage space: Apple menu → System Settings → General → Storage → Manage
Delete large files and downloads you don’t need
Empty Trash
Move large files to external storage or cloud
Keep at least 10–20% of storage free
Manage browser performance (clear unused tabs, remove heavy extensions)
Clear browser cache if it’s large
Reset browser settings if performance is degraded
Run First Aid on your drive: Disk Utility → select drive → First Aid
If using an HDD: consider upgrading to SSD (if supported by your model)
Ensure enough RAM (consider upgrading if your model allows)
Reduce visual effects: System Settings → Accessibility → Display (adjust Reduce motion/Transparency options)
Turn off or reduce widgets and desktop clutter
Use Energy settings: System Settings → Battery (or Energy Saver) → optimize for performance
Avoid running multiple heavy apps at once
Use fewer background sync services (cloud, photo libraries, backups) during performance-critical work
Check for malware: run a reputable security scan
Rebuild Spotlight index if search is slow: System Settings → Siri & Spotlight → Spotlight Privacy (toggle items) or follow Apple’s indexing steps
Reset NVRAM/SMC if applicable to your model (as directed by Apple)
Create a backup, then reinstall macOS if the system remains slow
Check peripherals and external drives for issues (disconnect and retest)