Sometimes the iPhone’s file system gets so badly confused that it stops reporting the correct amount of available free space. This can lead to inaccurate (and annoying) warnings about your phone running out of space, and no amount of pruning will solve the problem. There are a lot of factors that can contribute to this issue, but regardless of the cause, the fastest and easiest way to fix the problem is to restore from a local, encrypted iTunes backup. This rewrites the file system on your phone, removing any hidden files or misreported data and restoring your iPhone’s system to a clean state. You won’t lose any data, and you don’t even need to use an old backup.
Creating a Local iPhone or iPad Backup
First, you’ll need to create a local, encrypted backup of your iPhone on your computer’s hard drive.
1. Connect your iPhone to your computer’s USB port with a lightning cable.
2. If it doesn’t open automatically, open iTunes from the Applications folder.
3. Click on the iPhone icon in the upper left, near the playback controls.
4. Look for the “Backups” section and tick the radio button next to “This Computer.” This will make a backup on your computer’s hard drive rather than an iCloud backup.
5. Tick the checkbox that reads “Encrypt iPhone backup” underneath “This Computer.” An encrypted backup can include sensitive information like Health and Keychain data. If you don’t check this box, all that data will be deleted when we restore from backup.
6. When you’re ready, click the”Back Up Now” button.
7. Your iPhone will now begin the backup process. If you can, avoid using your iPhone while it’s backing up.
Restore iPhone Backups from iTunes
Now that you’ve recreated our backup, you can restore your iPhone from that backup file and reclaim some free space.
1. If you unplugged your phone, plug it back into your computer.
2. Under “Manually Back Up and Restore,” click the “Restore Backup …” button.
At this point you may get a warning saying you’ll need to turn off “Find My iPhone” before the restore can be completed. If this is the case, you can turn this off on your iPhone under “Settings -> iCloud”.
3. By default, the most recent backup will be selected for restoration. If you want to chose a different backup file, use the drop-down list next to “iPhone Name.”
4. Click the “Restore” button.
5. When prompted, enter your iTunes password to unlock the encrypted backup, then click the “OK” button.
6. Your iPhone will go into restoration mode, displaying the message “Restoring from Backup.” You won’t be able to use your phone until the backup is complete. For a 16 GB iPhone, the restoration process can take up to fifteen minutes. Larger phones will take longer to restore, so block out an hour of “no phone” time just to be safe. Keep your phone connected to your computer until the phone has restarted and the restoration is complete.
Restoring from an encrypted backup certainly isn’t the only way to free up storage space on your iPhone. But if no amount of deleting apps and files will convince your iPhone that you actually have available disk space, “resetting” the file system via backup is a relatively painless way to solve the problem.