macUSB is a guided macOS app for creating bootable USB media on Apple Silicon and Intel Macs from local .dmg, .iso, .cdr, and .app files, or with the built-in macOS downloader.

macUSB is and will always remain completely free. Every update and feature is available to everyone.
If the project helps you, you can support ongoing development:

Choose one installation method:

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

brew install --cask macusb

Project website: macUSB

As Apple Silicon Macs became the default host machines, creating bootable USB installers for macOS Catalina and older turned into a recurring support issue.

Common problems reported across forums and guides include:

• codesign and certificate validation failures on legacy installer paths,
• version-dependent compatibility constraints and tooling differences on newer hosts,
• manual terminal workflows that are easy to misconfigure and hard to verify.

macUSB was built through practical research and validated solutions developed during repeated troubleshooting of these legacy installer scenarios.

As adoption grew and feedback continued to come in, especially through Reddit discussions, macUSB expanded beyond legacy macOS USB creation. The app now includes a built-in macOS downloader and support for creating bootable Linux and Windows media, evolving into a more complete all-in-one tool for bootable USB workflows on Mac.

• Built-in Downloader: discover and download macOS installers available from Apple servers.
• Local source support: create bootable USB media from local .dmg, .iso, .cdr, and .app files.
• One guided flow: from source selection or download to finished bootable media.
• Apple Silicon legacy support: automatic compatibility handling for older macOS installers during USB creation.
• Automatic media prep: partition and format checks with conversion when required.¹
• Linux and Windows support: create bootable USB media from supported Linux and Windows .iso images.

1. Install macUSB using one of the methods listed in How to Download macUSB.
2. Open macUSB and either:
   • choose a local source image or installer (.dmg, .iso, .cdr, or .app), or
   • use the built-in Downloader to fetch a macOS installer from Apple.
3. Select the target USB drive and review the operation details.
4. Start the process and monitor bootable media creation stage by stage.
   • All data on the selected USB drive will be erased.
5. Use the final result screen for next steps.

Allow in the Background General → Login Items & Extensions

Full Disk Access Privacy & Security → Full Disk Access

Click any screenshot to open full size.

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

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

Windows Installer Windows workflow highlights UEFI-only media preparation and the MBR/FAT32 target format.

Click any screenshot to open full size.

1. Installer List Browse macOS installers available from Apple servers.

2. Download Progress Track download and preparation progress in real time.

3. Download Summary Review the final status and use the installer in the creation flow.

• Architecture: Apple Silicon or Intel.
• System: macOS 14.6 Sonoma or newer.
• Free disk space:
  • Downloader stage: up to 45 GB, depending on the selected macOS version.
  • macOS USB creation stage: up to 20 GB, depending on the selected source and system version.

• For macOS installers: at least 16 GB; 32 GB minimum for Sequoia and newer.
• For Windows/Linux images: 8 GB or more, depending on the size of the selected .iso image.
• Performance: USB 3.0+ is recommended.

macUSB can work with either local source files or the built-in macOS Downloader.

Accepted local source formats depend on the system recognized in the selected source:

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

macOS versions recognized and supported for USB creation:

macUSB recognizes Windows .iso images starting from Windows XP and Windows Server 2003.

Bootable Windows USB creation is currently supported for Windows 8 and newer and Windows Server 2012 and newer. Prepared media is UEFI-only.⁵

When a Windows image is recognized, macUSB detects the edition automatically. For ARM builds, the architecture is labeled directly in the detected name, for example Windows 11 (ARM).

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

brew install wimlib

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

When a Linux image is recognized, macUSB detects the distribution, version, and architecture automatically. ARM builds are labeled directly in the detected name, for example Linux - Ubuntu 26.04 (ARM).

If a selected file is a valid Linux image but is not recognized automatically, you can force Linux mode manually from Options → Skip file analysis → Linux.

Linux support has been tested with 19 distributions using the latest available releases as of April 30, 2026, with boot behavior verified on real hardware.⁶

If you are reviving a PowerPC Mac, the project website includes a dedicated Open Firmware guide based on real boot testing of PowerPC USB workflows created with macUSB.

Validated scenarios include:

• Mac OS X Tiger and Mac OS X Leopard boot scenarios,
• Single DVD editions, and for Tiger also the Multi-DVD path,
• Open Firmware boot commands verified in real hardware tests, including an iMac G5.

Use the step-by-step guide for setup and boot instructions.

PowerPC USB boot behavior can vary by model. During validation testing, USB boot was confirmed on an iMac G5, while an iBook G4 (2003) detected the USB device but did not boot from it successfully.

The interface follows system language automatically:

• 🇵🇱 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)

If you need help with macUSB or want to report a problem, use GitHub Issues.

Before opening an issue:

• check whether the same problem has already been reported,
• choose the issue template that best matches your case,
• attach diagnostic logs exported from Help → Export diagnostic logs...,
• attach screenshots showing the issue.

Licensed under the MIT License.

Copyright © 2025-2026 Krystian Pierz