: Use the macOS Catalina App Store link to open the store, then click Get . This downloads the installer to your Applications folder.
Release the key when you see the Startup Manager screen showing bootable drives. download macos catalina 10157 dmg file install
Note: You will need at least and up to 15-20GB of free storage space to safely complete the installation. Step-by-Step Installation Guide : Use the macOS Catalina App Store link
To install macOS Catalina 10.15.7, you must first obtain the (approx. 8GB), as the standalone DMG files available on the Apple Support Downloads page are typically Update patches (approx. 3GB) that require an existing Catalina installation. 1. Download the Full Installer Choose the method that matches your current device: Note: You will need at least and up
If you are coming from an older OS (like Mojave), Catalina also introduced: How to download and install macOS - Apple Support
Use the gibMacOS script to download the installer directly from Apple's servers. 2. Create a Bootable USB Installer You will need a USB drive with at least 16GB of space.