Why iPhone backups matter and what an external drive can do
An iPhone backup stored on an external hard drive gives you a complete copy of your phone's data — photos, messages, contacts, app settings, and more — that lives separately from your device and from Apple's servers. If your phone is lost, stolen, or damaged, you can restore everything to a new phone from that backup. An external drive also frees up space on your computer and keeps your backup under your control rather than relying solely on iCloud.
The catch is that iPhone backups are large — typically 50 GB to 200 GB depending on how many photos and videos you have — so an external drive makes practical sense. Your computer's built-in storage fills up fast if you back up regularly.
Key Takeaways
- iTunes or Finder (on Mac) creates encrypted backups that include everything on your iPhone, and you can move those backups to an external drive by changing where your computer stores them.
- Windows users need iTunes; Mac users with Catalina or newer use Finder instead, and both let you choose an external drive as the backup location.
- The backup process takes 15 minutes to over an hour depending on how much data you have and how fast your drive is.
- You must keep the external drive connected and in the same location every time you back up, or your computer will create a new backup on your internal drive instead.
How to move iPhone backups to an external drive on Mac
On a Mac running Catalina or newer, Finder handles iPhone backups instead of iTunes. Plug in your iPhone and your external hard drive, then open Finder and click your iPhone in the sidebar under Locations. Click the General tab, then check the box next to "Encrypt local backup" — this protects your backup with a password so anyone with access to the drive cannot read your data. Choose your external drive from the "Backup Location" dropdown menu.
Click "Back Up Now" and let the process finish. Finder will show a progress bar and tell you when it's done. The first backup takes longest because it's copying everything; later backups only copy what changed, so they run faster. Do not unplug the drive or close Finder until the backup completes.
After the backup finishes, you can unplug the external drive. The next time you plug in your iPhone and your external drive together, Finder will back up to that same drive automatically if you've set it as your backup location. If you plug in your iPhone without the external drive connected, Finder will ask where you want to back up — choose the external drive again to stay consistent.
How to move iPhone backups to an external drive on Windows
Windows users must use iTunes to back up an iPhone. read iTunes from the Microsoft Store or Apple's website, then plug in your iPhone and your external hard drive. Open iTunes and click the iPhone icon in the top left, then select the Summary tab.
Under "Backups," check the box next to "Encrypt iPhone backup" to password-protect your data. Click "This computer" to back up locally rather than to iCloud. Now you need to tell iTunes where to store the backup. Open File Explorer, navigate to C:\Users\[Your Username]\AppData\Roaming\Apple Computer\MobileSync\Backup, and cut the Backup folder. Paste it into a folder on your external drive, then create a shortcut or symbolic link pointing back to the original location — or use a third-party tool like iTunes Backup Extractor to redirect backups to your external drive.
The simpler approach: back up to your computer first using iTunes, then manually move the backup folder to your external drive using File Explorer. This takes more steps but avoids command-line work. After moving the folder, plug in your external drive before you back up again, and iTunes will find the backup in its new location.
What to do before you start backing up
Test your external drive first by copying a few files to it and reading them back. A new drive should work when ready, but a used one might have bad sectors that will corrupt your backup. Format the drive to Mac OS Extended (for Mac) or NTFS (for Windows) if it came formatted for a different system — this erases everything on the drive, so back up any files you want to keep first.
Make sure you have enough free space on the external drive. Your iPhone backup will be roughly the same size as the "iPhone Storage" number in Settings > General > iPhone Storage on your phone. If your phone shows 120 GB used, your backup will be around 120 GB, so your external drive should have at least 150 GB free to leave room for future backups and other files.
Connect the external drive to your computer with a USB cable and leave it plugged in during the entire backup process. A wireless or network drive will not work for iPhone backups — it must be a drive connected directly to your computer.
Restoring from a backup on your external drive
When you need to restore your iPhone from the backup on your external drive, plug in both your iPhone and the external drive to your computer. On Mac, open Finder, click your iPhone, go to the General tab, and click "Restore Backup." On Windows, open iTunes, click your iPhone, go to Summary, and click "Restore Backup." Your computer will show a list of available backups — select the one from your external drive and enter the encryption password you set up.
The restore process erases your iPhone and copies everything from the backup back onto it. This takes 30 minutes to over an hour depending on how much data you're restoring. Do not disconnect your iPhone or the external drive until the process finishes and your phone restarts.
Keeping your external drive backup current
Set a backup schedule and stick to it. Monthly backups are reasonable for most people; weekly backups make sense if you take a lot of photos or videos. The easiest way to remember is to back up whenever you update your phone's iOS — plug in both devices, run the backup, and you're done.
Keep your external drive in a safe place. If your phone and your backup drive are both destroyed in the same event — a fire, a flood, a theft — you've lost everything. Consider keeping a second backup on a different drive stored somewhere else, or use iCloud as a second backup location. You can have both an external drive backup and an iCloud backup running at the same time.
Check your backup occasionally by looking at the backup date in Finder or iTunes. If the date is months old, you haven't actually been backing up — usually because you forgot to plug in the external drive. Plug it in, run a backup, and update your routine so it happens more often.
Troubleshooting common backup problems
If Finder or iTunes says "backup failed," the most common cause is that the external drive disconnected during the backup. Plug the drive back in, make sure it has free space, and try again. If it keeps failing, the drive might be failing — try backing up to your computer's internal drive first to see if the problem is the drive or something else.
If you see two backups in Finder or iTunes and you're not sure which one is current, check the date and size. The most recent one with today's date is the one your phone just created. You can delete old backups by right-clicking them and selecting "Delete," which frees up space on your external drive.
If your external drive is not showing up in the backup location menu, make sure it's formatted correctly for your computer and that it's plugged in with a cable that works — try a different USB port or cable. Some external drives need their own power adapter; if yours has one, plug it in.
Frequently Asked Questions
Can I back up multiple iPhones to the same external drive?
Yes. Each iPhone creates its own backup folder, and Finder or iTunes keeps them separate. Plug in each phone one at a time and back them up to the same external drive. Your computer will manage multiple backups without mixing them up. Make sure the drive has enough space for all of them.
What happens if I unplug the external drive before the backup finishes?
The backup stops and may become corrupted. Your iPhone is not harmed, but the backup file might not work if you try to restore from it later. Plug the drive back in and start a new backup. Do not restore from a backup that was interrupted.
Do I need to encrypt my backup?
Encryption is optional but recommended. An encrypted backup is password-protected, so someone who gets your external drive cannot read your messages, passwords, or health data. An unencrypted backup can be read by anyone with access to the drive. The encryption password is separate from your iPhone passcode.
Can I use a cloud service like Google Drive or Dropbox instead of an external drive?
No. iPhone backups must go to a local drive connected directly to your computer, or to iCloud. Cloud storage services like Google Drive and Dropbox do not work as backup destinations for iTunes or Finder. If you want cloud backup, use iCloud instead, or back up to an external drive and then copy that backup to cloud storage separately.
How often should I back up my iPhone?
At least monthly, or whenever you have new photos or important data you do not want to lose. If you take photos daily or use your phone for work, back up weekly. The more often you back up, the less data you lose if something happens to your phone.