macUSB is a guided macOS app for creating bootable macOS USB installers on Apple Silicon and Intel Macs, from local .dmg, .iso, .cdr, and .app files or with the built-in 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, preparing bootable USB installers for macOS Catalina and older turned into a frequent support issue.

Common issues 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 from practical research and tested fixes gathered during repeated troubleshooting of these legacy installer scenarios.

• Built-in Downloader: discovers and downloads macOS installers available from Apple servers.
• Local source support: build bootable macOS USB installers from local .dmg, .iso, .cdr, and .app files.
• One guided flow: from source/downloader selection to final bootable media.
• Apple Silicon legacy support: automatic compatibility handling for older installers during bootable USB creation.
• Automatic media prep: partition and format checks with conversion when required.
• PowerPC-ready paths: dedicated support for Tiger/Leopard-era scenarios.

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

First launch note: macUSB requires two mandatory permissions for reliable installer creation: enable Allow in the Background for macUSB and enable Full Disk Access for macUSB in System Settings. Without these permissions, helper workflows may fail.

Allow in the Background General → Login Items & Extensions

Full Disk Access Privacy & Security → Full Disk Access

Warning: All data on the selected USB drive will be erased.

Click any screenshot to open full size.

1. Welcome Start the workflow.

2. Source & Target Choose local installer or Downloader, then select USB.

3. Operation Details Review process before start.

4. Creating USB Media Track stage-by-stage progress.

5. Operation Result Finish with next-step guidance.

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 final status and use the installer in creation flow.

• Processor: Apple Silicon or Intel.
• System: macOS 14.6 Sonoma or newer.
• Free disk space:
  • Downloader stage: 15–45 GB, depending on selected macOS version.
  • Installer creation stage: 10–20 GB, depending on target system version.

• Capacity: at least 16 GB; use 32 GB minimum for macOS 15 Sequoia and macOS 26 Tahoe installers.
• Performance: USB 3.0+ is recommended.
• External HDD/SSD support: installer creation on external hard drives is disabled by default on every app launch to improve safety and reduce the risk of accidental target selection. You can enable it in Options → Enable external drives support.

Accepted local formats for macOS installers:

• .dmg
• .cdr
• .iso
• .app

Or use the built-in Downloader to fetch installers available from Apple servers.

Systems recognized and supported for USB creation:

The table describes versions supported for bootable USB creation. Downloader availability depends on installers currently published by Apple.

A dedicated Open Firmware guide is available on the project website, based on real boot-testing of PowerPC USB workflows with installers created by macUSB.

Test coverage includes:

• 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 command usage verified in real hardware tests (including an iMac G5).

If you are reviving a PowerPC Mac, use this step-by-step guide.

Note: PowerPC USB boot support can vary by model, especially on older hardware. During validation testing, USB boot was confirmed on an iMac G5. On an iBook G4 (2003), the USB device was detected but still failed as a readable boot source.

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)

Use GitHub Issues for troubleshooting, bug reports, and feature requests.

Before submitting:

• use the appropriate issue template,
• attach diagnostic logs exported from Help → Export diagnostic logs...,
• attach screenshots showing the issue.

Licensed under the MIT License.

Copyright © 2025-2026 Krystian Pierz