How to Clear System Data Storage on Mac: 6 Safe Ways

What Counts as System Data on a Mac?

System Data is the successor to the category older macOS versions called Other. It contains a wide mix of items: application caches and temporary files, system and app logs, virtual memory swap files, local Time Machine snapshots, app support files, plug-ins and extensions, disk images and archives, and the old iPhone and iPad backups that Finder stores on your drive.

The reason the category feels so vague is simple: macOS lumps together everything that does not fit a clean bucket like Apps, Photos or Documents. That is also why the number fluctuates, sometimes within a single day — the swap file grows under memory pressure, and Time Machine quietly takes new local snapshots. Seeing this category reach tens of gigabytes is completely normal.

One important reassurance before you start deleting: not all System Data is junk. macOS manages swap files itself and automatically thins local snapshots when the disk starts filling up. The goal is not to force the category to zero, but to remove the stale part that is safe to delete — old caches, logs, unused backups and forgotten large files.

Check Your Storage Breakdown in System Settings

The first step is seeing what you are dealing with. On macOS Ventura and later, open the Apple menu, choose System Settings, go to General and select the storage screen. The colored bar can take a few minutes to calculate; once it finishes, hover over each segment to see how much space every category uses. On macOS Monterey and earlier, the same view lives under About This Mac in the Apple menu, on the Storage tab.

This screen also surfaces Apple's built-in recommendations: storing files in iCloud, an optimize-storage option that removes movies and TV shows you have already watched, and a setting that empties the Trash automatically after 30 days. You can also open the Applications category from the list and delete large apps you have not launched in months directly from there.

The screen has one big limitation, though: the System Data row is not clickable. Apple provides no breakdown of what is inside it, which is exactly why you need either the manual steps in the next sections or a disk analyzer that shows your drive at the file level.

Clear Caches, Logs and Old Downloads Safely

The safest place to start is browser caches, because they rebuild themselves after deletion. In Safari, enable the Develop menu from the Advanced section of Safari's settings, then use it to empty caches. In Chrome, Firefox and Edge, the clear-browsing-data option in each browser's privacy settings does the same job.

For user-level caches, open Finder, choose Go and then Go to Folder (Shift-Command-G), and enter ~/Library/Caches. Open the folders of apps you recognize and delete their contents — not the folders themselves. Never bulk-delete the Library folder and never touch anything under /System; that is precisely the risky forum advice this guide exists to replace. Log files can be reviewed the same way at ~/Library/Logs. Restart your Mac afterwards, which also clears the swap files that count toward System Data.

The Downloads folder is another quiet space consumer. Sort it by size and date; old .dmg installers and archives you have already used can usually be deleted without a second thought. Disk Mop brings these three chores together: its Cache Cleaner handles system and application caches, the Browser Cache Cleaner covers Chrome, Firefox, Edge and Safari, and the Downloads Cleaner categorizes old files so you can clear them in one click.

One more hidden item deserves a mention: local Time Machine snapshots. In Terminal, the command tmutil listlocalsnapshots / lists the snapshots currently on your disk. macOS deletes them on its own when space runs low, but if you need room immediately, you can run tmutil deletelocalsnapshots followed by the snapshot's date.

Empty the Trash and Remove Duplicate Files

Files in the Trash are not really gone — they still occupy disk space. Control-click the Trash icon in the Dock and choose to empty it, or better, open Finder's settings, go to Advanced and enable the option that removes items from the Trash after 30 days. That single setting stops storage from silently filling up again.

Old iPhone and iPad backups are another invisible line item in System Data, and each one can weigh several gigabytes. Connect your device, select it in the Finder sidebar and use the manage-backups button on the General tab to delete backups you no longer need. Because they are stored deep inside the Library folder, most users never realize they exist.

Duplicate files are the most commonly overlooked waste of space: photos exported twice, documents downloaded again and again, folders copied for safety and forgotten. Hunting them manually can take hours. Disk Mop's Duplicate Detector compares files by their SHA-256 hash, which means only byte-for-byte identical copies get flagged — so deleting one copy is completely safe.

See Exactly What Fills Your Disk with a Treemap

The core problem with fighting System Data is invisibility: Apple tells you the total but never shows the contents. A treemap visualization solves this at the root. Every folder on your disk is drawn as a rectangle proportional to the space it uses, so the biggest space consumers jump out at first glance.

Disk Mop's Disk Analysis feature scans your drive and builds exactly this treemap view. A cache folder that has ballooned out of control, a forgotten virtual machine image or a stack of disk images from years ago becomes obvious within seconds. The Large File Finder complements it by listing every file over 500 MB in a single view.

Disk Mop runs natively on macOS 12 and later, on both Apple Silicon and Intel Macs, and is notarized by Apple. You stay in control the whole time: the app only shows you what it found, and nothing is removed without your review. If you use both Windows and Mac, the same app covers both platforms.

Keep System Data from Growing Back

Clearing System Data is not a one-time job — caches and logs rebuild by design. A quick look at the storage screen once a month lets you catch growth early, which is far easier than doing a marathon cleanup when the disk-full warning appears.

A few simple habits make a big difference: restart your Mac regularly so swap files get cleared, keep the automatic Trash-emptying setting on, uninstall applications you no longer use, and give the Downloads folder a quick review at the end of each month.

If you would rather put the routine on autopilot, Disk Mop's Scheduled Cleanup creates weekly or monthly tasks that clean caches, remove old downloads and empty the Trash for you. The one-click Speed Up feature runs the same cleanup on demand, and the System Health Score shows your Mac's overall condition at a glance.