Click to download the "Install macOS Catalina.app" into your Applications folder. 2. Using the Terminal (The Pro Way)
sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Catalina --nointeraction download macos catalina 10157 dmg file better
Apple doesn't provide a direct "DMG" link on their website; instead, they provide an .app installer via the Mac App Store. 100% secure, signed by Apple, free. Click to download the "Install macOS Catalina
After it finishes, you have a bootable image ready to be converted or used. Direct Download Links (Third-Party) 100% secure, signed by Apple, free
The "better" way to download the macOS Catalina 10.15.7 DMG is to fetch the official installer via the and convert it yourself. This guarantees you aren't installing malware and that the OS will be stable for years to come.
If you are on a Windows PC and cannot use the methods above, you may look for mirrors on sites like Archive.org .