Using macOS Startup Key Combinations: A Complete Reference

Introduction / Why This Is Needed

Startup key combinations (or "boot keys") are a powerful tool for managing the macOS boot process. They allow you to start your system in special modes: Safe Mode, Recovery Mode, from an external disk, or to reset system settings. These modes are essential for diagnosing software issues, recovering from crashes, or installing a new version of macOS.

After reading this guide, you will confidently use all the essential key combinations for both Intel-based and Apple Silicon Macs.

Requirements / Preparation

Before using startup key combinations, ensure the following:

• Your Mac is connected to a power source (for laptops).
• You know your Mac's architecture: Apple Silicon (M1, M2, M3, etc.) or Intel. This is critically important, as the combinations and methods differ.
• For Recovery Mode, a stable internet connection is required if you plan to reinstall macOS.
• An external bootable media (USB drive) must be properly created using createinstallmedia (for macOS) or another tool.

Essential Startup Key Combinations

1. Safe Mode

Purpose: Boot with a minimal set of system extensions and verify the disk. Helps determine if a problem is caused by software conflicts or corrupted system files.

For Intel-based Macs:

1. Shut down your Mac (Apple menu → Shut Down).
2. Press the power button and immediately press and hold the Shift key.
3. Release the key when you see a progress bar or the Apple logo. Booting into Safe Mode will take longer than usual.

For Apple Silicon Macs:

1. Shut down your Mac.
2. Press and hold the power button until the "Startup Options" screen appears.
3. Select your startup disk (usually "Macintosh HD").
4. Press and hold Shift, then select "Continue in Safe Mode."
5. Release Shift after the boot process begins.

How to tell you're in Safe Mode: In the Apple menu (top-right corner), you will see "Safe Mode."

2. Recovery Mode

Purpose: Access the Disk Utility to repair a disk, reinstall macOS, access Terminal, or restore from a Time Machine backup.

For Intel-based Macs:

1. Shut down your Mac.
2. Press the power button and immediately press and hold Command (⌘) + R.
3. Release the keys when the Apple logo or a progress bar appears.

For Apple Silicon Macs:

1. Shut down your Mac.
2. Press and hold the power button until the "Startup Options" screen appears.
3. Select your startup disk and click "Continue." The system will automatically boot into Recovery Mode.

Available options in Recovery Mode:

• Disk Utility — for formatting and repairing disks.
• Reinstall macOS — for a clean installation.
• Restore from Time Machine — to revert to a previous state.
• Terminal — to execute command-line commands.

💡 Tip: To boot into Recovery Mode with the latest version of macOS (if you have multiple systems), use Option + Command + R on Intel. On Apple Silicon, the system always loads the latest compatible version.

3. Startup Manager (Select Startup Disk)

Purpose: Temporarily start macOS from an external disk (USB, Thunderbolt) or another internal partition without changing the default startup disk.

For Intel-based Macs:

1. Connect the external bootable media.
2. Turn on or restart your Mac and immediately press and hold the Option (Alt) key.
3. Release the key when icons for all available startup disks appear.
4. Use the arrow keys or your mouse to select the desired disk and press Enter.

For Apple Silicon Macs:

1. Connect the external bootable media.
2. Press and hold the power button until the "Startup Options" screen appears.
3. Select the external disk from the list and click "Continue."

4. Reset NVRAM/PRAM and SMC

NVRAM/PRAM stores certain system settings (e.g., startup disk selection, display brightness). SMC manages power, fans, and other hardware functions.

Reset NVRAM/PRAM

For Intel-based Macs:

1. Shut down your Mac.
2. Turn it on and immediately press and hold Option + Command (⌘) + P + R.
3. Hold the keys for about 20 seconds (on Macs with built-in speakers, you will hear the startup chime a second time).
4. Release the keys. Your Mac will restart.

For Apple Silicon Macs: NVRAM is reset automatically on every restart. No action is required.

Reset SMC

For Apple Silicon Macs: The SMC resets automatically. For a forced reset: shut down your Mac, wait 30 seconds, then turn it on.

For Intel-based Macs (Notebook with T2 chip):

1. Shut down your Mac.
2. Press and hold Control + Option + Shift on the keyboard for 7 seconds.
3. Without releasing those keys, press and hold the power button for an additional 7 seconds.
4. Release all keys and the button, wait a few seconds, then turn on your Mac.

For Intel-based Macs (Notebook without T2 chip):

1. Shut down your Mac.
2. Connect the MagSafe or USB-C power adapter.
3. Press and hold Shift + Control + Option on the keyboard and the power button simultaneously for 10 seconds.
4. Release all keys, then press the power button to turn on your Mac.

5. Boot into Internet Recovery Mode

Purpose: Boot into a Recovery Mode that connects to Apple's servers to download the latest version of macOS if your local recovery partition is damaged or missing.

For Intel-based Macs:

1. Ensure your Mac is connected to the internet via Ethernet or Wi-Fi.
2. Shut down your Mac.
3. Turn it on and immediately press and hold Option + Command (⌘) + R (or Shift + Option + Command + R for the latest version compatible with your Mac).
4. Release the keys when you see a spinning globe.

For Apple Silicon Macs: This feature is built-in. When selecting Recovery Mode via the power button, the system will automatically download the latest compatible version from the internet if the local recovery partition is unavailable.

Verify the Result

After booting into the selected mode, ensure everything is working correctly:

• Safe Mode: "Safe Mode" should appear in the Apple menu (top-right corner). Open "System Settings" → "General" → "About" to check.
• Recovery Mode: You should see the "macOS Utilities" window with icons for "Disk Utility," "Terminal," and others.
• Startup Disk Selection: The system should boot from the selected external or internal disk.
• NVRAM/SMC Reset: Check if settings have been reset (e.g., the startup disk selection returned to the default, display brightness is at maximum).

If the mode did not activate, ensure you held the keys immediately after pressing the power button (or after the chime on Intel) and released them only after the corresponding interface appeared.

Common Issues

Issue: Key combination does not work; Mac boots normally.

• Cause: You pressed the keys too late or released them too early.
• Solution: Shut down your Mac completely. Start holding the combination immediately after pressing the power button (or simultaneously with it on Intel). On Apple Silicon, use the "Startup Options" screen.

Issue: "Startup Options" screen does not appear on Apple Silicon Mac.

• Cause: Your Mac has already finished booting. The options screen only appears when you hold the power button before the Apple logo appears.
• Solution: Shut down your Mac, press and do not release the power button. After a few seconds, the options screen will appear. If the Apple logo appears, release the button and start over.

Issue: No internet in Recovery Mode.

• Cause: Wi-Fi is not configured in this mode, or there is no Ethernet cable.
• Solution: In the "macOS Utilities" window, open "Terminal" and enter networksetup -listallhardwareports to find the Wi-Fi interface. Then use networksetup -setairportnetwork <interface> <network_name> <password> to connect. Or connect your Mac via an Ethernet cable.

Issue: Settings did not change after NVRAM/SMC reset.

• Cause: The key combination was pressed incorrectly or held for insufficient time (for NVRAM on Intel, ~20 seconds is required).
• Solution: Repeat the procedure, strictly adhering to the time intervals. Ensure you are using the correct combination for your model (see sections above).

Issue: Safe Mode does not resolve the boot problem.

• Cause: The issue may be at the hardware level, with the disk, or firmware.
• Solution: Try booting into Recovery Mode and run "Disk Utility" to verify the disk (First Aid). If the disk is not repaired, you may need to reinstall macOS or replace the disk.