Check storage and background activity
- Open System Settings storage information and look for categories using unexpected space.
- Use Activity Monitor to sort CPU and Memory columns. Quit only applications you recognize.
- If Photos, iCloud Drive, or another service is syncing a large library, let it finish while connected to power.
Simplify startup and browsers
- Review Login Items and remove optional apps that do not need to start every time.
- Close unused browser tabs and remove unknown extensions.
- Test the same task in a fresh browser window to separate browser trouble from system-wide performance.
Update without using cleaner apps
- Back up important files and install a compatible macOS update.
- Update frequently used applications through the App Store or their official source.
- Avoid Mac cleaner pop-ups that use alarming warnings. Many create more problems than they solve.
Stop guessing when the problem keeps coming back
Ask for help when the Mac reports repeated storage errors, runs hot with no clear app open, restarts unexpectedly, or remains slow after a clean restart.