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MichaelMiller's avatar
MichaelMiller
Bronze Contributor
Mar 03, 2026

macOS High Sierra dmg download for making bootable usb insttaller

My old Macbook Air needs a clean reinstall as the disk was erased and no os on it. Currently, macOS High Sierra is the best option but I am unable to download the dmg file from Apple website. It only holds download for high sierra install app which only works on old Intel Mac.

Is there any app to let me download high sierra dmg file and create a bootable usb installer from it?

7 Replies

  • Kamrynim's avatar
    Kamrynim
    Iron Contributor

    If You Need a Bootable DMG Specifically:

    The official App Store download gives you an .app file, not a .dmg. If you specifically need a bootable DMG (for Hackintosh or Windows-based USB creation), you have two options :

    • Create it yourself: Download the official installer (.app), then use Terminal to convert it to a DMG or create a bootable USB
    • Third-party DMG repositories: Websites like Third-party tool offer pre-made DMG files, but these come with security risks

     

    If you're looking for the macOS High Sierra DMG download, some users consider using resources like sysin.org Blog Downloads. However, it's important to exercise caution when downloading macOS images from unofficial sources. While sysin.org Blog Downloads might offer a macOS High Sierra DMG download, these files may not be official or verified by Apple, which can pose security and stability risks.

    For the safest and most reliable macOS High Sierra DMG download, it's recommended to obtain the installer directly from Apple's official sources or through the Mac App Store if available. Using unofficial sources can lead to corrupted files or security vulnerabilities.

  • Briarouu's avatar
    Briarouu
    Copper Contributor

    If you are searching for the macOS High Sierra DMG download. Maybe it is time to consider using Uni-Beast, here's what you need to know:

    Using Uni-Beast for macOS High Sierra DMG Download

    When looking for the macOS High Sierra DMG download, some users turn to tools to create bootable installers or hackintosh setups. Uni-Beast is a popular tool used to create bootable macOS installers on USB drives, especially for installing macOS on non-Apple hardware.

    Steps to get the macOS High Sierra DMG Download:

    1. Obtain the macOS High Sierra DMG:

    For High Sierra, you may need to download the installer from Apple’s support pages or trusted sources.

    2. Prepare a USB Drive:

    Use Disk Utility to format a USB drive as Mac OS Extended (Journaled) with at least 8GB capacity.

    3. Create a Bootable Installer using Uni-Beast:

    Download and run Uni-Beast from tonymacx86 or other trusted sources.

    When prompted, select the macOS High Sierra DMG download as the source.

    Follow the instructions in Uni-Beast to create a bootable installer on your USB drive.

    4. Boot from USB and Install:

    After creating the bootable installer, restart your Mac or Hackintosh, boot from the USB, and follow the installation instructions.

  • Yhooum's avatar
    Yhooum
    Iron Contributor

    Mist is a dependable tool for downloading macOS High Sierra and creating bootable installation media. It bypasses all the tedious steps, fetching the installer directly from Apple's servers to swiftly create a fully functional USB boot drive for older hardware.

    User Guide: Download the software and navigate to the Installation Options tab. Locate the system and commence macos high sierra download. Upon completion, select the installer within the software, click the USB icon, and choose a USB drive with 16GB or greater capacity. The application will automatically format the drive and create a bootable installation disk. It generates the system swiftly without requiring command-line input.

    This solution is particularly useful for those using newer Intel or Apple silicon-based Macs who cannot directly run older installation programmes, enabling them to create a bootable drive for older MacBook Air models.

  • Olddies's avatar
    Olddies
    Silver Contributor

    This method allows you to create a bootable macOS High Sierra installer USB after you have completed the macos high sierra download and have the installer app in your Applications folder. It works on any Mac running macOS.

    What You Need

    • USB drive 
    • macOS High Sierra installer app 
    • A working Mac 

    1.Insert the USB drive into your Mac

    • Open Disk Utility.
    • Select the USB drive from the left-hand sidebar.
    • Click the Erase tab.
    • Set the format to Mac OS Extended  and the partition scheme to GUID Partition Table. Name it MyVolume
    • Click Erase to format the drive.

    2.Run Terminal commands

    • Open Terminal
    • Copy and paste the following command, replacing ‘MyVolume’ with your USB drive's name if different:

    sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

    • Enter your administrator password when prompted
    • Type Y and press Enter to confirm

    3.Wait for completion

    • The process will take 10–20 minutes, showing progress with Erasing Disk and Copying messages.
    • Do not interrupt the process. When finished, you will see "Install media now available at /Volumes/Install macOS High Sierra.

    This method provides a reliable approach to creating a bootable installer after downloading macOS High Sierra. Whilst it requires a certain level of familiarity with Terminal operations, it remains a trustworthy solution for generating installation media.

  • MarlonSP's avatar
    MarlonSP
    Brass Contributor

    You're correct that the Apple website only provides the macOS High Sierra installer for download, which is only usable on compatible Macs, and not the.dmg file you're looking for. I can suggest a couple of workarounds for Macos high Sierra dmg download without directly downloading from Apple:

    If you've downloaded the installer for macOS High Sierra from an Apple Store webpage or another source, you can use it to perform a clean install or upgrade. Here's how:

    1. Download the Installer: Ensure you have the correct Install macOS High Sierra.app file (named something like Install macOS High Sierra.app), not a .dmg file, which is used to create a bootable external drive.

    2. Open the Installer: Locate the downloaded .app file and double-click it to open the installer.

    3. Follow the Installer: Proceed with the installation as you would during a normal macOS installation process. Keep in mind that you can't install High Sierra on a newer macOS version without some extra steps or using a virtual machine.

    Important Note:

    macOS High Sierra (10.13) is an older version of macOS that is no longer supported by Apple. Therefore, it's not recommended for new installations unless you have a specific reason or requirement to do so.

    If you're on a newer version of macOS, the downloaded installer may not be compatible. You can still create a bootable USB drive for educational or testing purposes, but it's not recommended for regular use.

    Compatibility and Safety: About the Macos high Sierra dmg download. Be cautious when downloading and installing software from the internet, especially older versions of operating systems. Always ensure the source is trustworthy and the software you're using is compatible with your system.

  • TrappJean's avatar
    TrappJean
    Silver Contributor

    This method will typically install the latest supported version on your device, which may not always be the exact macOS High Sierra download version you require.

    Step 1: Open Safari on a compatible Mac.

    Step 2: Visit the Apple Support page to obtain the legacy macOS installer.

    Step 3: Locate the High Sierra entry and click Get.

    Step 4: This will launch the App Store and begin macos high sierra download, saving Install macOS High Sierra.app to your Applications folder.

    Step 5: Once complete, run the installer without closing it. Keep it open in Applications to create bootable media.

    If your Mac supports it, you can boot into Internet Recovery to reinstall macOS High Sierra directly.