If you have ever checked your storage settings on macOS, you have likely noticed a massive, mysterious category labeled System Data (formerly known as 'Other'). This category can often consume hundreds of gigabytes, leaving you with little room for your own files. In this guide, we will show you exactly how to identify what is inside this category and how to safely remove the bloat to reclaim your disk space.

Step 1: Check Your Current Storage Usage

Before you start deleting files, you need to see exactly how much space System Data is occupying. Click the Apple Menu in the top-left corner, select System Settings, navigate to General, and then click on Storage. Wait for the bar to calculate. The grey section represents System Data, which includes system caches, log files, browser cookies, and local Time Machine snapshots.

Step 2: Clear User Library Caches

One of the biggest contributors to System Data is the Cache folder. Applications store temporary data here to speed up processes, but these files often stay long after they are needed.

• Open Finder and click Go in the top menu bar.
• Hold the Option (Alt) key and click on Library when it appears.
• Navigate to the Caches folder.
• Select the files inside (Cmd + A) and move them to the Trash. Note: Do not delete the folders themselves, just the contents inside.

Step 3: Remove Local Time Machine Snapshots

If you use Time Machine, macOS saves local snapshots to your internal drive when your external backup disk isn't connected. These can take up massive amounts of space. To clear them:

• Open Terminal (via Spotlight or Applications > Utilities).
• Type the following command: tmutil listlocalsnapshots / and press Enter.
• If snapshots appear, type: tmutil deletelocalsnapshots [date] (replace [date] with the specific snapshot ID listed).
• Alternatively, simply turning Time Machine Off and back On in System Settings often flushes these files automatically.

Step 4: Clean Up Application Support Files

Even after you uninstall an app, its support files often remain in the System Data category. To find them:

• In Finder, go to ~/Library/Application Support.
• Look for folders named after apps you no longer have installed.
• Right-click those folders and select Move to Trash.

Step 5: Delete Old iOS Backups

If you have ever backed up an iPhone or iPad to your Mac, those backups are stored within System Data. These are often 30GB to 100GB+ in size.

• Go to System Settings > General > Storage.
• Scroll down to iOS Devices and click the 'i' icon.
• Select old backups and click Delete.

Step 6: Empty the Trash and Restart

Files moved to the Trash still occupy space on your drive. Right-click the Trash icon in your Dock and select Empty Trash. Finally, Restart your Mac. macOS often performs background maintenance scripts during a reboot that will recalculate and further reduce the reported System Data size.

💡 Pro Tip: Keep your software updated to avoid these issues in the future.