MacSonarHow to Free Up Disk Space on a Mac: 7 Safe Steps
Start by finding out what is actually using your storage. Then remove only files you recognise and no longer need. This guide walks through a careful order of operations, from Apple’s built-in Storage view to a final check of Trash.
If your Mac says its startup disk is almost full, you do not need to start by deleting mysterious folders. First inspect the storage breakdown, then look for personal files, old apps and backups you can identify. Treat caches and anything labelled “System Data” with extra care.
1. Check what is using space
On macOS Ventura 13 or later, open the Apple menu , choose System Settings → General → Storage. On older macOS versions, open About This Mac → Storage. Give the storage view time to calculate; use it as a map of categories, then open the available information buttons to inspect items before removing anything.
“System Data” (called “Other” on some versions) is a broad category for Apple and third-party files that do not fit a more specific category. It is not one folder and not a recommendation to erase system files. Apple explains the categories and built-in storage options.
2. Find large files you recognise
Look first for large videos, disk images, exported projects, archives and old installers in your own folders. In Finder, review Downloads, Documents, Movies and any project or backup folders you recognise. Sort or inspect by size where possible, then open an item or use Quick Look to confirm what it is.
If you still need a file but not on this Mac, copy it to an external drive or another storage location, verify the copy opens, and only then remove the local copy. Cloud syncing is not the same as a separate backup; check whether deleting a synced item also removes it from other devices.
3. Review Downloads and old installers
Downloads often collects duplicate installers and files kept “just in case.” Review the folder by date and size. Remove only items you can identify and replace: a downloaded installer is usually available again, while a personal archive or one-off export might not be.
Move selected files to Trash first. That gives you a chance to notice a mistake before you empty it. If you are unsure what a file is, leave it alone and search for its name or ask the app that created it.
4. Remove apps you no longer use
Use the Applications category in Storage or Finder to identify apps you recognise and no longer need. Quit an app before removing it, and follow the developer’s uninstall steps when the app includes a dedicated uninstaller. Some apps keep documents, libraries or settings outside the Applications folder; do not delete those blindly because they can contain work or preferences.
Apple’s guide to finding and deleting files describes which Storage categories can be opened for review.
5. Review device backups and media
Old iPhone or iPad backups, large video files and downloaded media can use substantial space. Check the date and device name before removing a backup, and keep a current backup if you may need to restore that device. In Photos, Music, TV and other libraries, use the app’s own controls when possible so you understand whether an action deletes a local copy, a synced copy or both.
If you use Apple’s storage recommendations, review what each option does before enabling it. Storing files in iCloud can reduce local copies while using your iCloud storage plan; it does not create unlimited free storage.
6. Handle caches and “System Data” carefully
Some caches are temporary and can be recreated, but cache folders are not all interchangeable. Deleting one can sign you out, remove app state, or make an app rebuild data the next time it opens. Developer build caches may be large, but removing them can mean slower builds while tools download or generate the data again.
Avoid instructions that tell you to erase everything inside ~/Library, /Library or a folder just because its name includes “cache.” Close the relevant app, confirm what created the data, and use that app’s cleanup controls or a trusted explanation of the specific folder. Never remove unfamiliar items from macOS system folders to chase a number in Storage.
If the storage chart's System Data number is the main concern, read our guide to what System Data includes and how to inspect it safely.
Useful rule: if you cannot explain what a file is and what will happen after it is removed, do not delete it yet.
7. Empty Trash only after checking
Moving a file to Trash does not free its disk space until Trash is emptied. Before emptying it, open Trash and scan the items one last time. Emptying Trash is a permanent deletion step; keep a separate backup for anything important.
After cleanup, return to System Settings → General → Storage and let macOS refresh the view. If you removed a large file but the number barely changes, check whether it remains in Trash, whether a copy is stored elsewhere, or whether Storage is still updating.
Common questions about Mac disk space
How do I find the largest files on my Mac?
Start with the Documents category in System Settings → General → Storage and inspect its large-file options. You can also review familiar Finder folders such as Downloads, Movies and project folders. Confirm each item before deleting it. Apple’s storage guide lists built-in ways to review documents, apps, backups and other categories.
Is it safe to delete cache files on a Mac?
Some caches can be recreated, but that does not make every cache folder safe to remove. The app may need to download or rebuild data, and some folders can contain state you care about. Identify the specific cache and its consequences first.
Why is “System Data” so large?
System Data groups different Apple and third-party files that do not belong to a more specific storage category. Its size can change as macOS and apps manage temporary data. Inspect known files and backups rather than deleting system folders to reduce the displayed number.
Does freeing disk space make a Mac faster?
Freeing space can help when low startup-disk space is contributing to a problem, but it does not guarantee a speed increase. Slow performance can have other causes too. Apple recommends checking available storage as one troubleshooting step, alongside other possible causes.
Do I need a Mac cleaner app?
No. macOS has built-in Storage tools for reviewing categories and removing items. If you use a third-party analyzer, choose one that explains what it found, shows the items before removal and lets you decide. MacSonar Space is currently accepting early-access registrations; downloads and purchases are not open yet.
Keep the cleanup deliberate
The safest way to free up disk space on a Mac is to work from visible, familiar files toward less obvious data, pausing whenever the consequence is unclear. Start with the Storage view, review personal files and old backups, and leave unfamiliar system data in place.
Sources: Apple Support: Free up storage space on Mac · Apple User Guide: Find and delete files on your Mac · Apple User Guide: Optimize storage space on your Mac.