If you’re looking to run macOS Big Sur on a virtual machine like VMware or VirtualBox, or just want a bootable backup, you’ll need an ISO file. Since Apple only provides the
installer, you have to build the ISO yourself using the Terminal. ⚠️ Compatibility Check
Before starting, ensure your Mac is compatible. Big Sur supports MacBook 2015+ MacBook Air 2013+ MacBook Pro Late 2013+ . You will also need at least 15GB-20GB of free space Step 1: Download the Installer
You can download the official "Install macOS Big Sur" app directly from the Mac App Store . Once finished, the installer will sit in your /Applications folder. Do not run it yet! Step 2: Create the ISO via Terminal
and run the following commands, which involve creating a blank disk image, mounting it, and using the createinstallmedia tool to flash the installer files. hdiutil create -o /tmp/BigSur -size
g -layout SPUD -fs HFS+J -type SPARSE hdiutil attach /tmp/BigSur.sparseimage -noverify -mountpoint /Volumes/installBigSur sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/installBigSur --nointeraction Use code with caution. Copied to clipboard
Finally, finalize the ISO by detaching, converting the sparse image to a CDR format, and saving the final BigSur.iso to your desktop.
hdiutil detach /Volumes/Install\ macOS\ Big\ Sur/ hdiutil convert /tmp/BigSur.sparseimage -format UDTO -o /tmp/BigSur.iso mv /tmp/BigSur.iso.cdr ~/Desktop/BigSur.iso Use code with caution. Copied to clipboard You now have a BigSur.iso file on your desktop, ready for your virtual machine. macos big sur iso 2021
As of late 2023, macOS Big Sur is no longer receiving security updates. If this is for a primary machine, consider a newer macOS version. How to download macOS Big Sur
While macOS Big Sur (version 11) officially retired in September 2023, it received a surprise security update (version 11.7.11) as recently as February 2026 to maintain FaceTime and Messages functionality until 2027.
If you are looking to create a bootable ISO for a 2021-era Mac or virtual machine, here is the current state of availability: Official Download Methods
Apple does not provide a direct .iso file. Instead, they offer the installer app, which you must convert yourself.
App Store: You can still find the macOS Big Sur page in the Mac App Store. Clicking "Get" will trigger the download via System Settings.
System Requirements: Ensure you have at least 20GB of free space for the download and roughly 15GB for the final installation. Creating the ISO from the Installer
Once you have the "Install macOS Big Sur" app in your Applications folder, use the following Terminal steps to create a 2021-compatible ISO: If you’re looking to run macOS Big Sur
Create a Blank Disk Image:hdiutil create -o /tmp/BigSur -size 14g -layout SPUD -fs HFS+J
Mount the Image:hdiutil attach /tmp/BigSur.dmg -noverify -mountpoint /Volumes/BigSurISO
Flash the Installer:sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/BigSurISO --nointeraction
Convert to ISO:hdiutil detach /Volumes/Install\ macOS\ Big\ Surhdiutil convert /tmp/BigSur.dmg -format UDTO -o ~/Desktop/BigSur.cdrmv ~/Desktop/BigSur.cdr ~/Desktop/BigSur.iso Key Considerations for 2026
Security: Although 11.7.11 provided a patch in early 2026, the OS is generally considered end-of-life (EoL). It lacks modern security updates found in macOS Monterey (12) or Ventura (13).
Hardware Compatibility: This is often the final OS supported by certain 2013-2014 MacBook Air/Pro models.
Are you looking to install this on original Mac hardware or a Virtual Machine like VMware or VirtualBox? How to download macOS Big Sur Looking Into "macOS Big Sur ISO 2021": Uses,
In the world of Apple operating systems, macOS Big Sur (version 11) represented a massive seismic shift. Released in late 2020 and dominating the spotlight throughout 2021, it introduced the biggest design overhaul in decades and laid the groundwork for Apple Silicon.
Even today, users frequently search for "macOS Big Sur ISO 2021." But why the specific search for an ISO file? Why the 2021 timestamp? And what are the dangers lurking in the shadows of these downloads?
Date: April 2026 (Retrospective look at the 2021 release) Target OS: macOS 11 Big Sur
When Apple launched macOS Big Sur (version 11.0) in November 2020 and continued updating it throughout 2021, it marked a seismic shift in Mac design language. For users searching for the term “macOS Big Sur ISO 2021,” you are likely looking for a portable, bootable disk image file to install or virtualize Apple’s 2021-era operating system.
But why is an "ISO" file for Big Sur so elusive? Let’s break down everything you need to know—legal considerations, creation methods, virtualization (VMware/VirtualBox), and troubleshooting.
Since you specifically want the 2021 version (not the final 11.7.10 release), you must fetch the specific build number. For Big Sur 2021, the target build is 11.4 (20F71) or 11.3 (20E232) .
The 2021 ISO is specifically required for VMware because newer macOS versions (Ventura+) require hardware NVRAM fixes that break on older VMware versions.
Configuration for VMware Workstation Pro 17:
BigSur2021.iso.F2 -> Virtualize CPU -> Enable “PMU Virtualization”.The 2021 ISO will install in roughly 15 minutes. Do not accept updates to Monterey during setup.