Does macOS Mojave Require Apfs?
Contents When You Install Mojave onto an Ssd, Hard Disk, or Fusion Drive, If That Is Still in Apple Extended (Hfs+) Format, the Installer Will Try to Convert...
When you install Mojave onto an SSD, hard disk, or Fusion Drive, if that is still in Apple Extended (HFS+) format, the installer will try to convert that storage to use APFS. There is no option for it to do otherwise.
Does Mojave convert to Apfs?
The current release version of Mojave is 10.14. 2: Get macOS Mojave. Converting from HFS+ to APFS will require reformatting the disk to APFS. Unless you require special protection in which case use APFS (Encrypted.)
Must Read
Should I use Apfs or Mac OS Extended?
Newer macOS installations should use APFS by default, and if you’re formatting an external drive, APFS is the faster and better option for most users. Mac OS Extended (or HFS+) is still a good option for older drives, but only if you plan on using it with a Mac or for Time Machine backups.