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Upgrading to a new version of macOS helps keep your computer secure and your information private. Read on for several ways to accomplish upgrades.
Overview
Apple releases a new version of macOS every fall. Keeping up with upgrades (moving from one named version to another) helps to keep your computer secure (since Apple only fully patches the latest version) and your data private (since new privacy features are introduced in each version).
Depending on your computer's hardware, there are a number of ways you can upgrade your Mac.
Methods
Before you Start, you'll need:
- A power adapter
- Your password for the account on the computer
- Backups of your important data
Software Updates window (preferred)
Use the built-in functions of macOS to run the upgrade from the same place you install minor updates. The built-in Software Updates should show you the latest OS that your computer can install.
- Launch the System Settings app (Apple Logo, System Settings, and search for Software Updates)
- Download and install the upgrade that is presented in the Software Updates pane.
Self Service.app for MHC-owned Macs (preferred)
You may be able to use a guided upgrade process to upgrade your Mac from one version to a new version. This may be helpful if System Settings does not show you the version you want, or if you simply would like a more guided process.
- In the Applications folder, open Self Service.app.
- Search for "Upgrade" or go to the OS or Updates category.
- You should see any guided upgrades that are available for your computer.
- Most computers can upgrade to macOS 14 Sonoma, macOS 15 Sequoia, or macOS 26 Tahoe (as hardware allows).
- For computers running macOS 12 Monterey or below, please contact the LITS Technical Support Helpdesk at asklits@mtholyoke.edu or 413-538-2600 for assistance.
- Run the upgrade installer for the version you want. The workflow will streamline a number of decisions for you and show messages to keep you informed along the way:
- Remind you to plug in your portable computer.
- Download the installer or update the installer if it was previously downloaded.
- Do a check to make sure you have enough free space.
- Ask you to confirm that you want to upgrade.
- Give you a warning 90 seconds before the reboot is necessary.
- You can continue to use the computer while it downloads the upgrade installer.
- A pause for several minutes while the process prepares the new recovery volume is normal.
Mac App Store download
In some cases, you may be able to download the installer app directly from the Mac App Store.
- Go to Apple's How to download macOS page
- Find the Use the App Store section
- Follow the link to the version you want (currently supported versions are macOS 14 Sonoma, macOS 15 Sequoia, and macOS 26 Tahoe).
All Upgrade Methods
- After the upgrade is downloaded and prepared, the reboot and upgrade may take 20 - 45 minutes. Exact duration depends on a number of factors such as CPU speed, memory, and disk size.
- Expect the system to run a little slow for the first 24 hours after an upgrade, as the system re-indexes the Spotlight search database in the background.
Troubleshooting
Slow system after upgrade
macOS needs to do a lot of work behind the scenes after an update, primarily updating the Spotlight file index and running a new snapshot of the system, and making sure the recovery partition is squared away.
Our Mac management system also will be making some changes -- different OS versions require some differences in settings. These changes will typically take place after the first reboot into the upgraded OS.
The Activity Monitor app in Utilities can show which applications and processes are consuming the most processor and memory, and is a great aid to troubleshooting.
System slowness should not persist past the first 24 hours, so if you're still experiencing this issue after 24 hours and a restart, please contact the LITS Technology Help Desk.
If things go wrong
Contact the LITS Technology Help Desk for your MHC-owned computer if you have issues with upgrading macOS. Here's some additional information for troubleshooting:
- If your computer seems stuck at the progress bar, move your mouse cursor to the right side of the progress indicator and walk away for at least five minutes. If the bar has moved beyond the cursor, you have progress, even if it's slow. Let it proceed.
- If you see an error message, you can consult Apple's page on troubleshooting install errors.