macUSB

One app for every bootable stick a Mac can make — macOS installers old and new, Windows, Linux, or a raw image written straight to the drive.

Homebrew cask Direct download

What it does

macUSB walks a bootable-media job from source to ejectable drive. The source can be a local .app, .dmg, .cdr, .iso or .img, or an installer fetched by the built-in downloader, which lists what Apple’s catalogues still publish — including public betas — and can keep the result as a read-only DMG. It then validates the target’s capacity, formats it for the chosen workflow, and reports each stage as it runs.

The reason it exists is the awkward end of the range. Building installer media for macOS Catalina and older on an Apple Silicon Mac means dealing with an Intel-only createinstallmedia; macUSB detects that, offers to install Rosetta when it is missing, and handles the rest. Support runs back to Mac OS X Tiger, with per-version caveats spelled out in the README rather than discovered at the failure.

It is not macOS-only any more. Windows .iso images are identified by family, service pack and architecture, formatted MBR/FAT32, and given the project’s own bootloader when the version needs legacy BIOS. An oversized install.wim is split into .swm parts with wimlib, and 64-bit Windows 10 and 11 media can carry a generated Autounattend.xml that skips the Microsoft-account requirement, pre-creates a local account, and blocks automatic BitLocker encryption. Linux images get distribution and architecture detection, and anything unrecognised falls back to raw image writing with a SHA-256 verify afterwards.

Notes

Needs Full Disk Access and Allow in the Background in System Settings. Without both, creation fails partway.
wimlib is not bundled — install it only if a Windows image trips the FAT32 4 GB file limit:

brew install wimlib

External HDD and SSD targets are hidden on every launch and must be re-enabled from Options each time, which is the right default for a tool that erases the drive it is pointed at.
Written in SwiftUI, notarised, MIT-licensed, and localised into thirteen languages.

Creating bootable media erases the whole target drive. macUSB shows the identifier and capacity on the confirmation screen — read it before starting, because nothing after that point is recoverable.

Alternative to

Alternative	Type	Trade-off
`createinstallmedia`	Built in	Ships inside the installer, and fails on the legacy combinations macUSB exists for
balenaEtcher	Open source	Writes raw images only — no macOS installer or Windows workflow
Mist	Open source	Downloads the installer but does not write the drive
CrystalFetch	Open source	Produces a Windows ISO, which still needs writing afterwards
Rufus	Open source	The reference for this job, and Windows-only
Ventoy	Open source	One stick that boots many ISOs, but no macOS installer handling