If you specifically need a pre-imaged file (like an .rdr ), these are typically hosted on community sites:
: Used in communities like ihackinOS to provide a full macOS installation that is bootable immediately once restored to a drive. download macos high sierra 10.13.5 image file -.rdr-
: You can often find High Sierra through a direct App Store link that may not appear in standard searches. If you specifically need a pre-imaged file (like an
: You can find various macOS High Sierra images, including ISO formats , which are useful for virtual machines. How to Use an .rdr Image File including ISO formats
The .rdr extension is not a native Apple format. In the context of macOS downloads, it usually refers to one of two things: