You now have a valid ElCapitan.dmg on your Desktop.
Once downloaded, the El Capitan installer will be in the Applications folder as an app. You can create a bootable USB drive or a DMG file for future installations.
Choose a location to save the DMG file and select "read/write" as the image format. download el capitan dmg
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.
This guide provides the official methods to obtain the installer, system requirements, and steps to create a bootable USB. Where to Download the Official OS X El Capitan DMG You now have a valid ElCapitan
If you are downloading the DMG to reinstall a Mac, you usually don't need the DMG file permanently; you need a .
: Go to the Mac App Store and search for "El Capitan." Choose a location to save the DMG file
You can use the built-in Terminal to convert the installer into a DMG or CDR (ISO-like) file.
Use Apple’s official installer download (Method 1) and create your own DMG if needed.