macOS

How to Update macOS High Sierra Safely and What to Know

macOS High Sierra (version 10.13) is an older major release, and the most relevant need today is knowing how to move safely if you are still on this version or supporting it. Th...

Mara Ellison
How to Update macOS High Sierra Safely and What to Know

Overview

macOS High Sierra (version 10.13) is an older major release, and the most relevant need today is knowing how to move safely if you are still on this version or supporting it. This guide explains how to update, when to consider staying or upgrading, how to prepare, and how to troubleshoot common issues. It assumes you are asking about update mac os high sierra in a practical, evergreen sense: how to handle High Sierra on Mac hardware today.

Update Safety and Compatibility

Before you update, confirm whether your Mac supports High Sierra, and whether it is appropriate to update it in your environment. Apple officially supports High Sierra on specific models, and keeping a system that old can affect security, app compatibility, and performance.

Supported Mac Models

High Sierra requires Macs introduced in 2009 or later, with some exceptions for specific models in each product line. Desktop and notebook models introduced in 2009 and newer generally support High Sierra.

Mac Type Earliest Supported Models Notes
iMac 2009 Early 2009 and later models
MacBook 2009 Mid-2009 and later
MacBook Pro 2009 Most 2009 and later models
Mac mini 2009 Early 2009 and later
Mac Pro 2010 Early 2010 and later

Security and App Compatibility Considerations

High Sierra receives no new security updates from Apple. Apps may decline to launch or disable features on such an old OS version over time. If your workflow depends on newer apps or services, updating macOS to a more recent release is recommended rather than staying on High Sierra.

Back Up Before You Update

Backing up is the most important step before installing any macOS update. It protects your settings, apps, documents, and workflow in case the update fails and you need to revert or restore your system.

  • Use Time Machine to create a full local backup to an external drive.
  • Verify the backup by checking file dates and testing restores of critical items.
  • Consider an offsite backup through cloud services or another Mac for added safety.

How to Update macOS High Sierra

Updating macOS High Sierra on a compatible Mac is straightforward using the Mac App Store or Recovery, depending on your current system state.

Check Current macOS Version

On the Mac, choose Apple menu > About This Mac to see the current version number and build. If you are already on High Sierra, the About window will display version 10.13 with a build number such as 17A365.

Download and Install High Sierra

If you are on an older version, you can update to High Sierra using the Mac App Store:

  1. Open the App Store app on your Mac.
  2. Search for macOS High Sierra and select Get or Update.
  3. Authenticate with your Apple ID and admin password when prompted.
  4. After download, the installer will launch; follow onscreen instructions to install.
  5. Restart your Mac when installation completes.

Install from Recovery if Needed

If you cannot install from the App Store, start from Recovery:

  1. Restart your Mac and hold Command-R at startup until the Apple logo or spinning globe appears.
  2. Select Reinstall macOS and follow the prompts.
  3. Agree to terms and choose the startup disk where High Sierra will be installed.
  4. Wait for the process to complete and restart when prompted.

Note: Recovery reinstallation preserves user files and apps by default, but it is still wise to back up first.

Troubleshooting Common Update Issues

Even with preparation, you may encounter problems during or after an update. These steps cover typical issues and safe first responses.

Stuck or Failing Installation

If the update appears stuck or fails, first ensure you have reliable power and storage space. Restarting the installer or using Recovery to reinstall macOS can resolve many issues. If the problem persists, disconnect nonessential peripherals and retry.

Post-Update Slowness or Bugs

After updating, you might notice slowness or odd behavior. Start by restarting your Mac, checking for app updates, and resetting preferences for apps that act strangely. If problems continue, consider repairing disk permissions (if offered by Recovery tools) or restoring from a known good backup.

Boot Issues and Safe Mode

If your Mac does not start normally, try Safe Mode to isolate software problems. To enter Safe Mode, restart your Mac and hold the Shift key until the login window appears. Safe Mode runs a check of your startup disk and disables extensions and some caches that can cause issues.

When to Stay on High Sierra or Upgrade Further

Deciding whether to remain on High Sierra or move to a newer macOS depends on your hardware, security needs, and app requirements.

Reasons to Upgrade Beyond High Sierra

  • Improved security updates that High Sierra no longer receives.
  • Compatibility with current versions of web browsers, productivity apps, and cloud services.
  • New features such as APFS, better memory management, and refined security controls.

Reasons to Stay on High Sierra (Temporarily)

  • Hardware that cannot run later macOS releases reliably.
  • Legacy software or peripherals that only work on High Sierra and are not yet updated.
  • A controlled environment where changes are carefully tested before deployment.

Best Practices for Maintaining macOS High Sierra

Whether you continue using High Sierra or plan to upgrade, following routine maintenance practices helps keep your Mac stable and secure.

  • Back up regularly with Time Machine and verify backups periodically.
  • Keep applications updated to their latest compatible versions.
  • Limit unnecessary startup items and extensions to reduce resource use and conflicts.
  • Monitor storage and maintain free space to support system operations and updates.

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