Diskpart is described as 'Command-line hard disk partitioning utility included in versions of the Windows NT operating system line from Windows 2000 onwards, replacing fdisk which was used in MS-DOS based operating systems' and is a partition manager in the os & utilities category. There are more than 25 alternatives to Diskpart for a variety of platforms, including Windows, Linux, KDE Plasma, Apple TV and GNOME apps. The best Diskpart alternative is GParted, which is both free and Open Source. Other great apps like Diskpart are Macrium Reflect, MiniTool Partition Wizard, EaseUS Partition Master and GNOME Disks.
MACRIUM REFLECT = backup software, not a partitioner