Download ~upd~ El Capitan Dmg File

Choose a location to save the DMG file and select "read/write" as the image format.

Open Disk Utility on your Mac.

Apple distributes old macOS versions as an (inside a .dmg wrapper for some versions) rather than a raw DMG of the OS. The closest official “DMG” is the InstallMacOSX.dmg you get from Apple’s link, which contains the installer. download el capitan dmg

Click Get → Download . The file “InstallMacOSX.dmg” (or “Install OS X El Capitan.app”) will appear in your Applications folder. Choose a location to save the DMG file