Essential Steps: How to Update macOS (Especially If Space is Low)

Keeping your macOS up to date is critical for security and performance. This guide will walk you through the standard update process and what to do if you encounter an error stating you do not have enough storage space.

Part 1: Checking for and Starting the macOS Update

The first step is to see if an update is available.

1. Click the Apple icon () in the top-left corner of your screen.

2. Select "System Settings..." (or "System Preferences" on older macOS versions).

3. In the sidebar, click "General", then click "Software Update" on the right.

4. Wait for your Mac to check for updates. If an update is available, click "Update Now" or "Upgrade Now".

5. Follow the on-screen prompts. Your Mac will need to restart to complete the installation.

DO NOT close the lid or disconnect power during the update.

Part 2: If You See a "Not Enough Space" Error

If you do not have enough free storage, the update will not start, and you will see a message like: "There is not enough free space on the selected volume to upgrade." This is very common, as updates can require 12GB to 35GB+ of free space.

You must free up storage before you can proceed.

Step 1: Check Your Available Storage

1. Go back to System Settings > General.

2. Click "Storage". You will see a bar graph showing what is using your space (e.g., Applications, Documents, macOS).

3. Look at the total available space listed at the top.
   

Step 2: Essential Ways to Free Up Space (Top Priorities)

Try these steps in order to clear enough space for the update.

1. Optimize Storage via Recommendations Under the "Storage" bar graph (in System Settings > General > Storage), you may see a "Recommendations" section.

• Turn on "Store in iCloud": This moves full-resolution photos and files to iCloud, keeping only optimized versions on your Mac.

• Turn on "Empty Trash Automatically": This will permanently erase items that have been in the Trash for more than 30 days.

2. Delete Large, Unused Files

1. Still in the Storage settings (General > Storage), look below the bar graph at the list (Applications, Documents, Mail, etc.).

2. Click the "i" icon next to "Documents".

3. Look at the "Large Files" tab. Sort by size and delete any very large files (like old movie files, zipped folders, or backups) that you no longer need. (Make sure you have a backup if these files are important!)

3. Move Large Files to External Storage If you have large files (like a massive photo or music library) that you must keep but don't need immediately accessible, move them to an external hard drive or a cloud storage service like Google Drive, Dropbox, or OneDrive. Once they are safely copied, you can delete them from your Mac.

4. Uninstall Unused Applications

1. In the Storage settings, click the "i" icon next to "Applications".

2. Sort by size. Look for large apps that you never use.

3. Select the application and click "Delete".

Part 3: Retry the macOS Update

Once you believe you have freed up enough space (aim for at least 35-40GB of free space to be safe, especially for major upgrades like macOS Sonoma):

1. Restart your Mac (Apple icon  > Restart...). This clears temp files and refreshes the system's storage calculation.

2. Go back to System Settings > General > Software Update.

3. Click "Update Now" or "Upgrade Now". The update should now begin the download and installation process.

Need Help?

If you have tried the steps above to free up space and are still receiving the storage error, please contact IT support for further assistance.