Help · Mac storage

How to move big folders to an external drive.

By Grant and Brad, who make Pangalin's apps · Updated 11 October 2026

When cleaning up isn't enough, the next step is moving big things you don't need every day onto an external drive: old projects, video footage, downloads, AI models, virtual machines. Done right, it frees tens of gigabytes without deleting anything.

Before you move anything

• A move is not a backup. Once moved, the drive holds the only copy. If it's lost or fails, so is the data. Back up the drive too (Time Machine can include external drives).
• Choose an APFS-formatted drive for Mac use. To check or change it, use Disk Utility. Reformatting erases the drive. Drives formatted MS-DOS (FAT) can't hold files over 4 GB, so avoid them. exFAT works with Windows too, but is slower and wastes space with many small files.
• Quit the app that uses the folder.

What's good to move, and what isn't

• Good: finished projects and footage, archives, installers you keep, downloaded AI models, virtual machines you rarely run, sample libraries.
• Use the app's own option: the Photos library, Music library, iPhone backups and Logic or GarageBand sound libraries should be moved the way the app or Apple describes, or the app can lose track of them. See iPhone backups for one example.
• Leave alone: your Library folder, the Applications folder and anything an app needs to start.

Move a folder with Finder

1. Connect the drive and open it in Finder.
2. Drag the folder onto the drive. Dragging to a different drive copies it, so the original is still on your Mac.
3. When the copy finishes, open a few files on the drive to check them, and compare the folder sizes with File › Get Info.
4. Only then move the original on your Mac to the Trash, and empty the Trash to get the space back.

Keep apps working with a link

If an app expects the folder in its old place, you can leave a symbolic link there that points to the new location. Apps follow it as if the folder never moved, while the drive is connected. Finder's own aliases don't work for this; you need Terminal:

ln -s "/Volumes/MyDrive/Projects" "$HOME/Projects"

Replace the drive and folder names with yours, and run it only after the original folder has been moved away. When the drive is unplugged, the link stays but leads nowhere until you reconnect. To undo, delete the link and copy the folder back.