What Is Using Up Storage on Your Mac?
System Data is often the largest and most confusing category. macOS groups caches, logs, Time Machine local snapshots, Spotlight indexes, and temporary files under this label. System Data can consume 20-60 GB on a Mac that has been in use for a year or more, and macOS does not provide a built-in way to see what is inside it.
Documents typically includes everything in your home folder — Desktop files, Downloads, project files, and media. Click the Documents category in Storage settings to see a list of your largest files sorted by size. Applications shows the storage used by installed apps, and macOS shows the operating system itself.
Understanding where your storage is going is the first step to cleaning it up. The sections below address each category with specific cleanup actions. For a broader look at storage recovery strategies, our guide to freeing up disk space on Mac covers complementary methods.
How Do You Clean Up Duplicate Files on Mac?
Duplicates accumulate silently. Every time you download an email attachment twice, save the same file from a browser, import photos from a camera, or copy files between folders, a duplicate is created. Over months and years these identical copies consume significant storage without providing any value.
DupScan scans your selected folders and groups identical files together based on their SHA256 hash — a cryptographic fingerprint of the file contents. Two files with the same hash are byte-for-byte identical regardless of their filename or location. DupScan displays each group with thumbnails and file details so you can choose which copies to keep.
Auto-Select speeds up the cleanup process by automatically marking older copies for deletion while keeping the newest version of each file. All deletions go to Trash, so you can recover any file within 30 days. Our complete guide to finding duplicate files on Mac covers the full process from scanning to deletion.
How Do You Clean Up Large Files on Mac?
Open Finder and navigate to your Downloads folder. Sort by size (View → Show View Options → Sort By → Size) to see the largest files first. Disk images and installers are safe to delete after you have installed the associated software. Video exports and zip archives should be reviewed individually.
DupScan's Large Files feature provides a faster approach. It scans your selected folders and displays the 100 largest files with QuickLook thumbnails, so you can visually identify what each file is before deciding to keep or trash it. Our guide to finding large files on Mac explains both Finder-based and DupScan-based methods in detail.
Pay special attention to your Desktop. macOS defaults to saving screenshots on the Desktop, and these files accumulate over time. A single Retina screenshot is 5-10 MB. Hundreds of forgotten screenshots can consume over a gigabyte.
How Do You Clean Up Cache and Temporary Files?
Application caches store temporary data to speed up app performance. Over time, these caches grow to several gigabytes — especially for browsers, media apps, and development tools. Open Finder, press Cmd+Shift+G, and type ~/Library/Caches to see all application cache folders.
Each folder inside ~/Library/Caches corresponds to a single application. You can safely delete any folder here. The application will rebuild its cache on the next launch, which may cause a brief slowdown the first time. Check folder sizes before deleting — some caches are only a few megabytes and not worth clearing.
Browser caches deserve special attention because they grow the fastest. Safari stores its cache in ~/Library/Caches/com.apple.Safari, and Chrome uses ~/Library/Caches/Google/Chrome. Clear these through each browser's built-in settings (Safari → Settings → Privacy → Manage Website Data, or Chrome → Settings → Privacy → Clear Browsing Data) rather than manually deleting the folders.
Temporary files in /tmp and /var/folders are cleaned automatically by macOS on reboot. Restarting your Mac is the simplest way to reclaim this space without manual intervention.
How Do You Clean Up Other Storage on Mac?
Time Machine creates local snapshots on your Mac's internal drive, even when your backup drive is not connected. These snapshots allow you to recover files from recent changes. macOS is supposed to delete old snapshots when disk space is low, but this process is not always immediate.
To see your current snapshots, open Terminal and run "tmutil listlocalsnapshots /". To delete all local snapshots, disable Time Machine in System Settings → General → Time Machine, wait a few minutes, and then re-enable it. This forces macOS to purge all existing local snapshots.
iOS device backups stored on your Mac can consume 10-50 GB each. Check for old backups in System Settings → General → Storage → iOS Files (or in Finder → your device → Manage Backups). Delete backups for devices you no longer own or that are backed up to iCloud instead.
System logs in /var/log and ~/Library/Logs accumulate over time but rarely consume more than a few hundred megabytes. Application support files in ~/Library/Application Support persist after uninstalling apps. Check this folder for folders belonging to apps you have already deleted.
How Do You Clean Up iCloud Storage on Mac?
Optimize Mac Storage works with iCloud Drive, iCloud Photos, and Messages in iCloud. When enabled, macOS tracks which files you access frequently and keeps those files downloaded locally. Files you have not opened recently are offloaded to iCloud — they still appear in Finder with a cloud icon and download instantly when you open them.
iCloud Photos with Optimize Storage is particularly effective for large photo libraries. Full-resolution photos and videos are stored in iCloud while your Mac keeps only lightweight thumbnails. A 100 GB photo library might use only 5-10 GB of local storage with this setting enabled.
Desktop & Documents Folders syncing moves these folders to iCloud Drive. Combined with Optimize Storage, files you rarely access are automatically offloaded. This is especially useful on Macs with smaller SSDs where local storage is limited.
Cleaning up iCloud storage itself is a separate task. Delete old files from iCloud Drive, remove large attachments from Messages, and clear out unnecessary iCloud Photos. Reducing your iCloud usage may allow you to downgrade to a less expensive storage plan.