macUSB

The all-in-one bootable USB creator for Mac

!Platform !Architecture !License !Security

📥 How to Download macUSB

Choose one installation method:

1. GitHub Releases: Download the latest release
2. Homebrew:

brew install --cask macusb

🔍 Why macUSB Exists

Creating bootable USB installers for macOS Catalina and older on modern Macs, especially Apple Silicon models, can be challenging because legacy installer workflows often conflict with newer system requirements. macUSB was created to make this process guided and reliable through solutions developed and verified during practical troubleshooting.

Thanks to user feedback, macUSB has grown beyond legacy macOS installer creation to include an integrated macOS downloader and support for creating bootable Linux and Windows media, evolving into an all-in-one tool for bootable USB workflows on Mac.

✅ Key Features

• Built-in downloader: discover and download macOS installers, including available Public Beta releases, from Apple servers.
• Local source support: create bootable USB media from local installers and disk images.
• Checksum calculation: calculate SHA-256 checksums for supported .dmg, .cdr, and .iso sources, as well as manually selected raw .img images.
• Apple silicon legacy support: automatic compatibility handling for older macOS installers during USB creation.
• Automatic media preparation: validate target capacity and prepare the selected drive for the chosen workflow.
• Linux and Windows support: create bootable USB media from supported Linux and Windows .iso images, with optional Windows setup automation.

⚡ Quick Start

[!WARNING]

Creating bootable media erases all data on the selected drive, SD card, or volume.

1. Install macUSB using one of the methods listed in How to Download macUSB.
2. Open macUSB and either:

1. Select the target USB drive or SD card and review the operation details.
2. Start the process and monitor bootable media creation stage by stage.
3. Review the final result and safely eject the media directly from the final screen.

[!IMPORTANT]

Enable Full Disk Access and Background App Activity for macUSB in System Settings. These are required by the app’s current installer download and media creation workflows.

• Full Disk Access: macUSB requires this permission to write to the selected external drive and build installers in the Downloader. On Macs with the Apple T2 Security Chip and on Apple silicon Macs, Removable Volumes access alone was insufficient for all required write operations, even with administrator privileges.
• Background App Activity: macUSB uses a helper registered through Apple’s SMAppService. This setting is required for the helper to run and perform privileged operations, such as preparing installers, formatting media, and writing data.

Background App Activity General → Login Items & Extensions

Full Disk Access Privacy & Security → Full Disk Access

🧭 Workflow Details

Click a screenshot to view it at full size.

macOS Installer Review the selected macOS version, target USB drive, and creation steps before starting.

Linux Image The Linux workflow includes guidance for handling the expected unreadable-disk prompt shown by macOS during creation.

Windows Installer The Windows workflow offers optional configuration for selected Windows restrictions and first-run setup choices.

🌐 macOS Downloader

The built-in downloader lets you browse and download macOS and older OS X installers directly from Apple servers. macUSB downloads the required files, verifies their integrity, and prepares a ready-to-use installer.

• Version selection: by default, the list shows the latest available stable release in each system family. Downloader options can show all available versions and Public Beta releases, which are hidden by default.
• Downloaded installer detection: recognized installers in /Applications are marked as downloaded in the list.
• Disk space checks: before downloading, macUSB checks the free space needed to prepare the installer, including optional DMG output.

Click a screenshot to view it at full size.

1. Installer List Browse available system versions and select an installer to download.

2. Download Progress Track progress, download speed, and each stage of installer verification and preparation.

3. Download Summary Review the result, reveal the completed installer in Finder, or send it directly to the USB creation workflow.

By default, the completed installer is saved as an .app in /Applications. To save it as a disk image, enable Save installer as a disk image (.dmg) in Downloader options and choose a destination folder. macUSB creates a read-only DMG containing the installer and removes the source .app after the image is successfully created. You can keep the image for later use or use it immediately to create bootable USB media.

⚙️ Requirements

Host Computer

• Architecture: Apple silicon or Intel.
• System: macOS Sonoma 14.6 or later.
• Free disk space:

Target Media

• Supported media: USB drives and SD cards in built-in Apple readers or external readers.
• Capacity: macUSB calculates the minimum required capacity from the installer or source image size, with a 5% allowance, and checks the selected drive or volume before proceeding.
• Performance: USB 3.0+ is recommended for USB drives and external readers.

[!NOTE]

External HDD/SSD support is disabled by default each time the app launches to improve safety and reduce the risk of accidental target selection. It can be enabled from Options → Enable external hard drive support.

Source Inputs

Accepted local source formats:

• For macOS: .dmg, .cdr, .iso, and .app
• For Windows/Linux: .iso

🍎 macOS Support

macUSB supports creating bootable USB installers across the macOS, OS X, and Mac OS X system families, from macOS Golden Gate 27 through Mac OS X Tiger 10.4. Some systems have additional requirements or limitations.[^1]

On Macs running macOS Golden Gate, Rosetta is not installed by default. It is required for installers from OS X Yosemite through macOS Catalina that include an Intel-only createinstallmedia tool. macUSB checks for Rosetta automatically and, when needed, offers to install it with one click.

[!NOTE]

For Mac OS X Lion 10.7 and later, hold Option (⌥) while selecting the target to reveal existing HFS+ volumes on GPT-partitioned USB drives or SD cards. Choosing a volume erases only that volume, without repartitioning the entire drive or affecting its other volumes.

[^1]: System-specific requirements and limitations:

- macOS Golden Gate 27: Creating its bootable USB installer is supported only on Macs with Apple silicon. The Mac used to create the installer does not need to be running macOS Golden Gate. - macOS Sierra 10.12: Only 10.12.6 is supported. - OS X Mavericks 10.9: Fully verified with the image from Mavericks Forever. Other sources may fail. - Mac OS X Tiger 10.4: Single-DVD images are auto-detected. For Multi-DVD images, only the first disc is recognized correctly. Other discs may appear as unrecognized or be identified incorrectly. To use them, force detection manually from Options → Skip file analysis → Mac OS X Tiger 10.4 (Multi DVD).

🪟 Windows Support

macUSB recognizes original Microsoft Windows .iso images from Windows XP through Windows 11 and Windows Server 2003 through Windows Server 2025, and automatically detects their Windows family, optional Service Pack, and architecture.

Bootable USB creation is supported for Windows Vista through Windows 11 and Windows Server 2008 R2 through Windows Server 2025. Windows XP and Windows Server 2003 are recognized but are not supported for media creation.

Available boot modes depend on the Windows version:

• Legacy BIOS only: Windows Vista, Windows 7, and Windows Server 2008 R2.
• Legacy BIOS or UEFI: Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 through 2022.
• UEFI only: Windows 11 and Windows Server 2025.

For 64-bit Windows 10 and Windows 11 images, macUSB can optionally prepare an Autounattend.xml file. It can automate selected first-run options, including local-account creation, language and region transfer, skipping selected network and privacy steps, bypassing the Microsoft account requirement, and preventing automatic BitLocker device encryption. For Windows 11, it can also bypass supported hardware checks.

Regardless of the selected boot mode, macUSB formats the target as MBR with FAT32. Because FAT32 has a 4 GB limit per file, some modern Windows images may require extra preparation. If install.wim exceeds that limit, macUSB automatically splits it into smaller .swm parts using wimlib.

[!IMPORTANT]

wimlib is required only when the selected Windows image contains an install.wim file that must be split. It is not bundled with macUSB and must be installed separately by the user. The simplest way to install it is with Homebrew:

>

> brew install wimlib

> macUSB automatically checks whether wimlib-imagex is available when this step is required.

🐧 Linux Support

macUSB also supports creating bootable USB media from Linux .iso images.

When a Linux image is recognized, macUSB attempts to detect its distribution, version, and architecture automatically. Images with Linux signals but without a recognized distribution can still use the Linux creation workflow. The detected name explicitly identifies ARM builds, for example Linux - Ubuntu 26.04 (ARM).

[!NOTE]

Linux support has been tested with 19 distributions.[^2]

[^2]: Validated distributions: Ubuntu, Kali Linux, NixOS, Garuda Linux, openSUSE Leap, Gentoo, Rocky Linux, Linux Mint, Fedora Workstation, Manjaro, Zorin OS, CachyOS, AlmaLinux, Debian, Arch Linux, MX Linux, Pop!_OS, EndeavourOS, and elementary OS. Testing covered the latest versions available as of April 30, 2026. Boot behavior was verified on a 2017 MacBook Air, a Dell OptiPlex 5040 with UEFI, and an ASUS F52Q with legacy BIOS.

💾 Raw Image Writing

macUSB can write .iso and .img files directly to external USB drives using Tools → Write a Raw Image to a Drive….

This method can also be used when a Linux image is not recognized during analysis.

After writing a Linux or raw image, macUSB verifies the written data against the source using SHA-256.

[!NOTE]

The resulting media is not guaranteed to be bootable. Bootability depends on the structure and compatibility of the source image.

🧩 PowerPC Notes

For instructions on booting a USB installer created with macUSB on a PowerPC Mac, see the Open Firmware USB boot guide.

[!NOTE]

USB boot compatibility depends on the Mac model and its Open Firmware version. Not every PowerPC Mac can boot from USB.

🌍 Available Languages

By default, the interface follows the system language automatically. A supported language can also be selected manually from Options → Language:

• 🇵🇱 Polish (pl)
• 🇺🇸 English (en)
• 🇩🇪 German (de)
• 🇯🇵 Japanese (ja)
• 🇫🇷 French (fr)
• 🇪🇸 Spanish (es)
• 🇧🇷 Portuguese (pt-BR)
• 🇨🇳 Simplified Chinese (zh-Hans)
• 🇷🇺 Russian (ru)
• 🇮🇹 Italian (it)
• 🇺🇦 Ukrainian (uk)
• 🇻🇳 Vietnamese (vi)
• 🇹🇷 Turkish (tr)
• 🇳🇱 Dutch (nl)
• 🇮🇷 Persian (fa)

🛠️ Troubleshooting

If you encounter a problem or have a question, please open an issue.

⚖️ License

Licensed under the MIT License.

Copyright © 2025-2026 Krystian Pierz