While Apple’s iCloud eliminates the need for many to back their iPhones or iPads up through iTunes on their Mac or PC, many users find restoring from iCloud to be too slow, or like to keep making secondary backups through iTunes.
Over time, those automatic or manual backups can hog up a lot of space on your hard drive. Fortunately, it’s simple to delete older backups, or backups for devices you no longer own in order to free up precious disk space.
To delete a backup, you’ll first need to launch iTunes. Then, select the ‘iTunes’ item in the menu bar, and click Preferences. Next, select the Backup tab. You should now see a list of all your iOS device backups:
You can now delete each backup individually by selecting the backup, and clicking the Delete Backup… button. After deleting all the backups you want to delete, just click the OK button, and iTunes will do the rest! Note: itunes may lag for up to 5-10 minutes before closing the window, as it deletes each backup from your drive.