macOS · Troubleshooting

Start Up macOS In Minimal Diagnostic Mode

Safe Mode starts your Mac with only essential system software and drivers loaded, skipping login items, most fonts, and system caches. It's a diagnostic first step used to determine whether a startup problem is caused by third-party software or a deeper system issue.

How to open Safe Mode

  1. Shut down the Mac completely.
  2. On Apple silicon Macs, press and hold the power button until 'Loading startup options' appears, then hold Shift while clicking Continue in Safe Mode; on Intel Macs, hold Shift immediately after powering on.
  3. Log in if prompted; you should see 'Safe Boot' in the login window or About This Mac.
  4. Test the issue, then restart normally (without holding any keys) to exit Safe Mode.

What you should know

  • Skips loading non-essential kernel extensions, login items, and startup apps.
  • Automatically runs a basic check of the startup disk during boot.
  • Clears certain system caches, which can resolve some performance or startup glitches on its own.
  • Disables some features and apps temporarily, like video capture in certain apps, while active.

The Mac will run noticeably slower in Safe Mode and some apps or features won't work — this is expected and not a sign of a new problem.

Why it matters

Safe Mode is often the fastest way to tell whether a crash or slowdown is caused by something you installed versus a deeper macOS or hardware fault, saving time before jumping to a full reinstall. It's a standard first troubleshooting step Apple Support itself asks users to try.

Best practices

  • Try Safe Mode before more drastic steps like reinstalling macOS or erasing the disk.
  • Note whether the problem you're diagnosing actually goes away in Safe Mode — that result matters for next steps.
  • Remove or update suspect login items and extensions if Safe Mode resolves the issue.

Common problems and fixes

The Mac won't enter Safe Mode no matter how the keys are held.
Make sure you're pressing Shift immediately at the right moment (right after the startup chime/logo on Intel, or from the startup options screen on Apple silicon), and try again after a full shutdown rather than a restart.
A problem persists even in Safe Mode.
This suggests the issue isn't caused by a third-party login item or extension; consider checking hardware diagnostics or reinstalling macOS from Recovery.

Tips and tricks

  • Check About This Mac while in Safe Mode — it should say 'Boot Mode: Safe' near the software details, confirming you're actually in Safe Mode.

Frequently asked questions

Will Safe Mode delete any of my files or apps?

No, Safe Mode is purely a diagnostic startup mode and doesn't remove or change any files, apps, or settings.

Why is everything slower and some apps missing in Safe Mode?

Safe Mode intentionally skips loading non-essential software and disables some graphics acceleration, so reduced performance and limited app functionality are expected while it's active.

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