A popular open-source script on GitHub that downloads the official files directly from Apple's servers, ensuring authenticity while allowing you to create your own DMG. Summary Table Method App Store Regular Mac users Highest Terminal Advanced Mac users Highest Google Drive Fast downloads/Non-Mac users Internet Archive Long-term backup/ISO needs
Ensure you save the 8.2 GB DMG to an SSD with 20+ GB free space. Do not download to a USB 2.0 drive.
https://drive.google.com/file/d/1ABC123xyz... (replace with a known community-verified link – but for this article, we assume you search for “macOS Catalina 10.15.7 DMG Mr. Macintosh” – Mr. Macintosh provides safe Google Drive mirrors).
Once you've downloaded the DMG file, follow these steps to install macOS Catalina 10.15.7: