To backup iPhone to external hard drive Mac directly using Finder on macOS Catalina or later, you need to redirect the default backup location by creating a symbolic link in Terminal, which forces all future backups to save to your external drive instead of your Mac's internal storage. This method frees up valuable space on your Mac while giving you physical control over your backup data.
Why backup your iPhone to an external hard drive on Mac?
Local backups on an external drive save your Mac's internal storage from being consumed by large iPhone backup files. You retain complete physical control over your data without relying on cloud storage limits. This guide applies exclusively to macOS Catalina (10.15) and later, where Finder manages iPhone backups instead of iTunes.
Before you start: Prepare your Mac and external drive
Connect your external hard drive to your Mac using a USB cable and ensure it has enough free space to accommodate your iPhone backup. A critical warning: if you already have iPhone backups stored in the default location on your Mac, manually back up those existing backups to another location before proceeding. The steps below will replace the default backup folder with a link to your external drive, and any existing backup files in the original folder will become inaccessible unless you move them first.
Step 1: Locate the default iPhone backup folder
Open Finder. From the "Go" menu in the Finder menu bar, choose "Go to Folder." Type or copy and paste ~/Library/Application Support/MobileSync/Backup/ in the pathname window and press Return. This reveals the folder where Finder normally stores iPhone backups. Verify its contents so you know what is currently there before making changes.
Step 2: Create a new backup destination on your external drive
In Finder, select your external hard drive from the sidebar. Create a new folder on the drive by right-clicking inside the Finder window and selecting "New Folder." Rename this folder something descriptive, such as "iPhone Backups." This dedicated folder will serve as the new home for all your iPhone backup files.
Step 3: Use Terminal to redirect the backup location
Open Terminal from your Applications folder (within Utilities). Enter the following command, then press Return: ln -s /Volumes/YourDriveName/iPhone\ Backups ~/Library/Application\ Support/MobileSync/Backup. This creates a symbolic link that redirects Finder to save backups to your external drive instead of the original location on your Mac. If you want to use Lacie external hard drive, substitute "YourDriveName" with the name of your Lacie drive when typing the command.
Step 4: Back up your iPhone in Finder
Connect your iPhone to your Mac using a cable. If asked, click "Allow" to let the accessory connect. Open Finder and select your iPhone from the sidebar under Locations. If necessary, trust your device. At the top of the Finder window, click "General." Select "Back up all of the data on your iPhone to this Mac." To save Health and Activity data from your device or Apple Watch, select "Encrypt local backup" and create a password. You cannot recover your backup without this password. Click "Back Up Now."
Step 5: Verify the backup on your external hard drive
After the backup completes, open a new Finder window and navigate to your external hard drive. Open the "iPhone Backups" folder you created. You should see a new folder with a long string of letters and numbers, representing your iPhone backup. The presence of this folder confirms the symbolic link is working correctly and that your backup files are now stored on the external drive.
Troubleshooting common issues
Backup not showing up on external drive: If the backup folder appears empty or the backup still saves to your Mac, double-check that the symbolic link was created correctly. In Terminal, run ls -la ~/Library/Application\ Support/MobileSync/ and verify that "Backup" shows as a symbolic link pointing to your external drive path. If it shows as a regular folder, the link failed and you need to repeat Step 3.
Symbolic link not working: Ensure your external hard drive is formatted as APFS or Mac OS Extended (Journaled). Drives formatted as exFAT or NTFS may cause the link to fail. Also confirm the drive is mounted and visible in Finder before running the Terminal command. If you need to backup files with Seagate external hard drive, the same formatting requirements apply, format your Seagate drive to Mac OS Extended if it is not already.
Drive not recognized: If your external drive does not appear in Finder after connecting, try a different USB cable or port. Some drives require external power, make sure the power adapter is connected. If you need to copy one external hard drive to another on mac, use Finder's drag-and-drop method after both drives are mounted, but do not attempt this while a backup is in progress.
Restoring from backup: Choose the appropriate backup from the list. If you want to transfer photos from iPhone to Seagate external hard drive separately, use the Image Capture app on your Mac instead of the backup process.
