file (e.g., for virtual machines or deployment tools), you must create it manually from the installer app using the command in Terminal. How to download and install macOS - Apple Support (SA)
Download the app using one of the methods above. Macos Big Sur Dmg Download
If you specifically need a DMG (e.g., for deployment or archiving), follow this safe method: file (e
If the App Store link isn't working or you prefer the command line, you can use tools like softwareupdate in the Terminal, though this often just triggers the same download process. If your Mac is older, use OpenCore Legacy
If your Mac is older, use OpenCore Legacy Patcher (OCLP) – but that requires advanced skills.
Only use Big Sur if absolutely necessary (e.g., running legacy 32-bit audio software or older Adobe CS). For daily use, upgrade to macOS Monterey or later.
Many sites claim to offer “macOS Big Sur.dmg” for direct download.