Apple does not provide a direct .iso file. Instead, they offer the installer app, which you must convert yourself.

Downloading macOS from unofficial sources can be risky. Always prefer the official Apple App Store. Mac OSX Big Sur ISO : Free Download, Borrow, and Streaming

This article provides a comprehensive overview of how to obtain and create a macOS Big Sur ISO, with specific relevance to versions released around 2021. Why Use a macOS Big Sur ISO?

If you want to run macOS Big Sur inside a virtual machine on a Windows or Linux PC using VMware, VirtualBox, or QEMU, the virtualization software generally requires an ISO file to boot the installer.

Run macOS in a virtual machine on other hardware for testing.

For a step-by-step visual on executing these terminal commands and verifying the output: How to Create macOS Big Sur ISO image Mac2iPhone YouTube• 14 Jan 2021 4. Alternative: Pre-made ISOs How to download and install macOS - Apple Support (IN) 23 Dec 2025 —

Allocate at least 4 Cores, 4GB to 8GB of RAM, and enable EFI booting.

If you are using VMware Workstation, you may need to apply a "patch" to support macOS.

While Apple provides the "Install macOS Big Sur" application in the App Store, it is not a direct .iso or .dmg file that can be readily used in virtualization software or on non-Apple hardware. An ISO file acts as a universal disk image, making it easy to mount, boot, and install.

To create a macOS Big Sur ISO (2021) , you must first obtain the official installer from Apple and then use Terminal to convert it into a bootable disk image. Apple does not provide direct ISO downloads; they only offer the installer. 1. Requirements