macOS Big Sur ISO 2021: Complete Download and Creation Guide
Released in late 2020 and updated throughout 2021, macOS Big Sur (version 11) marked a major shift in Apple's operating system, featuring a refined design, improved Safari performance, and support for Apple Silicon. While Apple provides the installer via the App Store, users often need a macOS Big Sur ISO for clean installations on virtual machines like VMware Workstation or VirtualBox. Minimum System Requirements
Before downloading or creating your ISO, ensure your hardware meets the following standards: Memory: At least 4GB of RAM.
Storage: 35.5GB available for upgrades; up to 44.5GB for earlier releases.
Compatible Macs: MacBook (2015+), MacBook Air (2013+), MacBook Pro (Late 2013+), Mac mini (2014+), iMac (2014+), and Mac Pro (2013+). Step 1: Download the macOS Big Sur Installer
To create an ISO, you must first have the official "Install macOS Big Sur.app" from Apple. macOS Big Sur - Technical Specifications - Apple Support
An ISO file for macOS Big Sur is primarily used for installing the operating system on virtual machines like VirtualBox or VMware. While Apple does not provide official ISO files directly, you can create one using the official installer on a Mac or find pre-built versions on archival platforms. Download Sources for Big Sur
If you need the installer to create an ISO, use these official or community-vetted links:
App Store (Official): Download the full installer for macOS Big Sur directly on a compatible Mac.
Mr. Macintosh (Direct Apple Links): Find a database of direct InstallAssistant.pkg download links hosted on Apple's servers at Mr. Macintosh.
Internet Archive: Download pre-made ISO files, such as version 11.6.5, from the Internet Archive macOS collection. How to Create a macOS Big Sur ISO
If you have a Mac, you can create your own ISO using Terminal with these steps:
Download the Installer: Get "Install macOS Big Sur" from the App Store.
Create a Disk Image: Open Terminal and create a temporary disk image:sudo hdiutil create -o /tmp/BigSur -size 16384m -volname BigSur -layout SPUD -fs HFS+J
Mount the Image:sudo hdiutil attach /tmp/BigSur.dmg -noverify -mountpoint /Volumes/BigSur macos big sur iso 2021
Create the Install Media:sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/BigSur --nointeraction
Convert to ISO: Eject the volume, convert the DMG to a CDR, then rename it to ISO:hdiutil eject -force /Volumes/Install\ macOS\ Big\ Surhdiutil convert /tmp/BigSur.dmg -format UDTO -o ~/Desktop/BigSur.cdrmv ~/Desktop/BigSur.cdr ~/Desktop/BigSur.iso Key Details (2021 Context) How to download macOS Big Sur
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
Must be running macOS Mojave or later to download the full installer. Disk Space:
At least 16GB of free space for the installer and additional space for the ISO creation. Big Sur Compatibility:
2013-2015 models or newer depending on the specific line (e.g., MacBook Air 2013+, MacBook Pro Late 2013+). Apple Support 2. Download the Big Sur Installer
You can download the official "Install macOS Big Sur" application through these methods: App Store: macOS Big Sur App Store page . This will open Software Update to start the download. Terminal Command:
Use the following command to download the installer directly to your Applications folder:
softwareupdate --fetch-full-installer --full-installer-version 11.7.10 Direct Link: If the App Store fails, verified databases like Mr. Macintosh provide direct links to Apple’s servers for the InstallAssistant.pkg Apple Support 3. Create the ISO Image (Step-by-Step) Once "Install macOS Big Sur.app" is in your Applications folder, run these commands in Terminal one by one: 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/BigSur Create the installation media:
sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/BigSur --nointeraction Unmount the volume: hdiutil detach /Volumes/Install\ macOS\ Big\ Sur Convert to ISO format:
hdiutil convert /tmp/BigSur.dmg -format UDTO -o ~/Desktop/BigSur.cdr Rename to .iso: mv ~/Desktop/BigSur.cdr ~/Desktop/BigSur.iso Stack Exchange
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 — macOS Big Sur ISO 2021: Complete Download and
Each macOS includes the latest built-in apps available for that macOS, including Safari, Mail and Apple Music (formerly iTunes). * Apple Support macOS Big Sur - App Store - Apple
During the shift towards the Apple silicon era in 2021, macOS Big Sur (version 11) emerged as a pivotal release. While Apple typically distributes its operating systems through the App Store, advanced users, developers, and IT professionals often require a standalone macOS Big Sur ISO file for virtualization in software like VMware or VirtualBox. The Significance of the ISO Format
An ISO file is a complete disk image of an optical disc. Since Apple does not directly provide official ISO downloads, creating one manually became a standard procedure for those needing to install macOS on non-Apple hardware or virtual machines. In 2021, this was especially common as users tested the compatibility of the new interface and features with their existing workflows before fully committing to the update. Creation Process via Terminal
Generating a macOS Big Sur ISO involves several technical steps using the Mac Terminal:
Apple does not officially distribute macOS Big Sur as an ISO file; they only provide the full installer app via the Mac App Store. To get a 2021-spec ISO for virtual machines (like VMware or VirtualBox) or Hackintosh builds, you must manually create it using a Mac and the Terminal. How to Create a macOS Big Sur ISO (Terminal Method)
Use the createinstallmedia tool on a Mac to convert the official App Store installer into a bootable ISO.
Download: Ensure "Install macOS Big Sur" is in your Applications folder.
Create/Mount Image: Run hdiutil commands to create a 16GB disk image and mount it.
Flash & Convert: Use createinstallmedia, then convert the file from .dmg to .cdr using hdiutil, finally renaming it to .iso. Requirements & Resources
Where to get an official Big Sur 11.2 ISO… - Apple Communities
softwareupdate (requires a Mac).gibMacOS (GitHub) on Windows/Linux to fetch Apple signed files and build your own ISO.Final note: The last “Big Sur” 2021 release is 11.6.1 (build 20G224). Anything labeled “11.7+” is actually macOS Monterey or later. For compatibility, stick to 11.6.1 if you need a pure 2021-era version.
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. Legal & Alternate Sources
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:
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
macOS Big Sur from a 2021 perspective, it was a landmark release that bridged the gap between traditional Intel-based Macs and the new Apple Silicon (M1)
. While its visual overhaul was highly praised, users in 2021 also faced some stability and compatibility hurdles. Core Highlights (2021 Perspective)
Since macOS Big Sur is technically a older operating system (released in 2020, with the final 11.x update released in late 2021), a "review" of a macOS Big Sur ISO 2021 typically refers to evaluating its use for virtual machines (VMs) rather than a review of the OS itself.
Here is a review breakdown of the macOS Big Sur ISO, specifically regarding its utility, stability, and use case in 2024/2025.
sudo hdiutil attach ~/Desktop/BigSur.dmg -noverify -mountpoint /Volumes/BigSurISO
Check the file size and integrity:
ls -lh ~/Desktop/BigSur.iso
# Should be ~12–14 GB
shasum ~/Desktop/BigSur.iso