Backup: discrepancies between disk usage and backup size

Your iMazing backup may be noticeably smaller than the total storage used on your Apple device. This is expected behavior. Not all data on your device is included in a backup.

Music and Videos are not part of the backup. These need to be exported and imported separately: select the Music & Videos tab in the left sidebar, then use the Import/Export options in the bottom toolbar. This matches how Apple's own backup works: excluding media libraries avoids duplicating files that can take up considerable space.

If you are unsure whether all your device data has been backed up, open the backup in iMazing's backup browser to verify its contents. Apps appear under File System > Apps, not in a separate section. If anything looks wrong, delete the backup and run a new one.