How to reinstall macOS from Recovery

Reinstalling macOS replaces the operating system on your Mac with a fresh copy, a standard fix when the Mac will not start or a repair has failed, and Apple says it does not remove your apps or personal data. Steps are given for both Apple silicon and Intel-based Macs.

What you need

• A Mac plugged into power, with the lid open if it is a laptop.
• An internet connection. Apple says you need a broadband connection that uses DHCP, over Wi-Fi or an Ethernet cable. Networks that need a login page, use 802.1X security or use PPPoE (a type of internet sign-in) can block the installation. A home router is normally fine.
• Your Mac login password. If the disk is encrypted with FileVault, it is also needed to unlock the disk.
• Time. The Mac may restart several times and sometimes shows an empty screen for minutes. The length depends on your connection and your Mac.

Step 1: Start macOS Recovery

Apple silicon Mac

1. Shut down the Mac. If it will not shut down, hold the power button for up to 10 seconds.
2. Press and hold the power button until Loading startup options appears, then release it.
3. Click Options, then click Continue.
4. If asked, select your startup disk and click Next. If asked, select a user you know the password for, click Next, and enter the password.

Intel-based Mac

Which keys you hold decides which macOS version is installed. See the table below this list.

1. Shut down the Mac, then press the power button.
2. Immediately hold Command + R until you see an Apple logo or a spinning globe.
3. If asked, join a Wi-Fi network or attach an Ethernet cable.
4. If asked, select your startup disk and user, and enter the password.

On an Apple silicon Mac, Recovery installs the current version of the most recently installed macOS. If you upgraded and then erased the disk with Disk Utility, you may get the version you had before the upgrade.

Step 2: Reinstall

1. In the Recovery window, choose the option to install or reinstall macOS. It is named Reinstall macOS followed by the version. Click Continue.
2. Follow the on-screen prompts.
3. When you are asked where to install, choose Macintosh HD. If you also see Macintosh HD - Data, do not choose that one.
4. If asked to unlock the disk, enter your Mac login password.
5. Wait. Do not let the Mac sleep and do not close the lid. It may restart several times and may show a blank screen, a progress bar or a message for a long time.

When it finishes, the Mac shows the login window or the Setup Assistant. Sign in with your usual account. Your apps and files should be as you left them.

If something goes wrong

• A globe with a warning symbol appears: the Mac could not reach the internet. Check your connection, try an Ethernet cable, try another network or try again later. See Mac Wi-Fi problems.
• Recovery will not load on an Intel Mac: try Option-Command-R instead of Command-R. Wait a few seconds after pressing the power button before you press the keys, so the Mac can recognize the keyboard. If the Mac will not shut down, hold the power button for up to 10 seconds first.
• The installer cannot see the disk: Apple suggests that erasing the startup disk in Disk Utility is a troubleshooting step. Read the warning below first.

Bring back your files from a backup

If you do have a Time Machine backup and your account or files are missing afterward, restore them. Apple describes using Migration Assistant: connect the backup disk, open Migration Assistant from the Utilities folder in Applications, choose to transfer from a Time Machine backup, and select the backup and categories. The transfer can take hours.

Frequently asked questions