How to free up space on your Mac in 2026

A full disk makes a Mac feel old before its time. macOS needs free space to swap memory, update itself and cache what you are working on, so once you are under about 10% free everything gets slower. Here is the order we use, safest first.

1. Empty the Trash and the Downloads folder

Obvious, and still the biggest win for most people. Sort Downloads by size and look at the top ten. Disk images (.dmg) and installer packages (.pkg) from apps you already installed are pure dead weight.

2. Clear app caches

Every app keeps a cache in ~/Library/Caches. Browsers, Spotify, Slack and design tools can hold gigabytes each. Caches rebuild themselves, so clearing them is safe; the first launch afterwards is a little slower, that is all. Do not clear caches for an app while it is running, and leave Apple's own caches alone.

3. Developer leftovers

If you have ever installed Xcode, look at ~/Library/Developer/Xcode/DerivedData and iOS DeviceSupport. On the Macs we tested, these two folders alone held between 10 and 40 GB. DerivedData is regenerated on the next build. Device support files are only needed for the iOS versions of devices you still connect, and Xcode re-downloads them anyway.

npm, pip, Homebrew and Docker keep their own caches too. Docker's disk image is worth a special look: it only ever grows.

4. Old iPhone and iPad backups

Backups made through Finder live in ~/Library/Application Support/MobileSync/Backup and are often the single largest thing on a laptop. Keep the newest backup for each device and remove the rest. Better still, switch that device to iCloud backup.

5. Large and duplicate files

Videos, disk images, exported project files. Sort by size, then by last opened. A file you have not opened in a year is a candidate for external storage. For duplicates, compare contents rather than names; two files called "final.mov" can be different, and two different names can be the same file.

6. Apps you no longer use

Dragging an app to the Trash leaves its support files behind. Use an uninstaller that finds the leftovers, or check ~/Library/Application Support and ~/Library/Containers yourself.

7. Cloud files that are downloaded locally

iCloud Drive, Google Drive and Dropbox all keep local copies of files you have opened. On iCloud, right-click a file in Finder and choose Remove Download; it stays in iCloud and comes back when you open it.

What not to do

• Do not delete anything inside /System, /Library or ~/Library that you cannot name.
• Do not trust "System Data" as a category to clean; it is a bucket macOS uses for many things, and most of it is meant to be there.
• Do not use a cleaner that deletes instead of trashing. Mistakes should be reversible.

AI Mac Cleaner does steps 2 through 7 for you, shows every file first, and moves them to the Trash rather than deleting them.