If you've been using a Mac for a while, sooner or later you'll have to create a bootable macOS drive on a USB or external hard driveWhether you need to install a new version, recover a computer that won't boot, or perform a clean installation, having a bootable installer on hand can save you a lot of trouble.
In this guide you will see, in great detail, how Create a bootable drive from macOS with and without TerminalWhat you need to prepare before starting, the differences between Intel Macs and Apple Silicon when booting from USB, and what to do if something goes wrong and you lose data. All explained in clear, conversational Spanish, but without leaving out any important aspects.
What is a macOS bootable installer and what is it used for?
When we talk about a "bootable" or bootable USB drive, we are referring to an external drive capable of booting the Mac on its own, without requiring the internal disk system to be running. It is, basically, a complete macOS installer that lives on a USB drive, SSD, or external hard drive.
Creating this type of installer is essential if you want perform a clean or scratch installationIn this type of installation, the contents of the Mac's internal disk (system and data) are completely erased, so the system is reinstalled as if it were brand new, reducing the likelihood of carrying over errors, corrupted configurations, or remnants of beta versions.
In addition, a boot drive is very useful when you need Install or update macOS on multiple computers without re-downloading the system on each one, or if you have an unreliable internet connection that cuts out when you try to update your Mac from the App Store.
Another typical scenario is when the team It won't start or it freezes on startupIn these situations, having a bootable USB drive allows you to enter the macOS installer, access Disk Utility, attempt to repair the system, reinstall, or even mount the internal disk to recover files.
Prerequisites for creating a bootable drive from macOS
Before you start working with the installer, it's a good idea to be clear about what Hardware and software requirements You need to comply. It's nothing out of the ordinary, but if you fail at one of them, the process can freeze or produce strange errors.
First, you're going to need an external drive with at least 16 GB of usable capacityIt can be a USB flash drive, a portable SSD, or even a hard drive, but it's more common to use a USB drive of 16 GB or more. Keep in mind that it will be completely erased, so back up any important data on it.
Also, you need a Mac compatible with the macOS version that you're going to install. For example, to create a macOS Ventura installer, the Mac must be on the list of computers supported by that version. If you try to force an incompatible version, the installation might not complete, or the computer might display a prohibition symbol (a circle with a diagonal line through it) at startup.
It is essential to have Internet connection on the Mac during part of the processThis is especially true when the installer needs to download additional firmware or other components specific to the Mac model. Even if the base system is on the USB drive, Apple may require additional data for that particular computer.
Finally, it is essential to download the full macOS installer from the Mac App Store (or from Apple's official downloads section for older versions). It should appear in the Applications folder as "Install macOS" and not simply as a small "stub" file that only launches the download.
Download the macOS installer from the Mac App Store
The first practical step is to obtain the complete system package which you'll use to create your bootable USB drive. The easiest way is to use the Mac App Store itself, which manages the download and places the installer in the correct location.
In the case of recent versions, such as macOS Ventura, you can Open the App Store and search directly for the version name.Type “Ventura” in the search box, go to the macOS Ventura page, and click the “Get” button. The software update panel will then open and the download will begin.
When the download process is complete, the macOS installation wizard windowIf your intention is to create a bootable USB drive and not install macOS yet, you should close the wizard. The correct procedure is to go to the top menu and select the "Quit macOS Setup" option.
After doing this, the file “Install macOS Ventura.app” (or the corresponding version) should now be there. saved inside the Applications folderIt is from there that the media creation tool (createinstallmedia) will take the content to copy it to the USB.
Prepare and rename the USB drive or external hard drive
With the installer downloaded, it's time to prepare the USB drive or external drive that you will use as a boot deviceThe process involves formatting and giving it a simple name to avoid confusion in the commands.
The general requirement is that the unit has a minimum of 16 GB of available space. On modern computers and for macOS versions like Ventura, it is recommended to format the drive as “Mac OS Extended (Journaled)” or “APFS” using Disk Utility, although many guides still suggest Mac OS Extended (Journaled) as the standard option for installers.
Once the USB drive is formatted, it's very convenient. Rename the volume with a short, space-free identifierFor example, “USB”, “VenturaUSB”, or something similar. This can be done directly from the Finder: select the volume icon on the desktop and rename it as you would any folder.
This name is important because it appears within the path “/Volumes/VolumeName” that you will use in the installer creation command. If you use spaces (like “My Bootable USB”), you will then have to escape those spaces with “\” in Terminal, which can lead to errors if you type quickly.
Remember All contents of the USB drive will be deleted during the process. So, if you had files there that you were interested in, move them to another drive before continuing to avoid any unpleasant surprises.
Create a bootable macOS USB drive using Terminal
The official and most flexible method for creating a bootable drive involves using the Terminal application and the createinstallmedia tool which Apple includes within the macOS installers. Although it might seem a little daunting at first, it's actually just a matter of copying and pasting a command correctly.
To start, open Terminal from the Utilities folder (within Applications) or using Spotlight. Make sure the USB or external drive you're going to use is already connected, formatted, and named as you chose in the previous step.
Each version of macOS has its own createinstallmedia path, but the structure is always similar. For macOS Ventura, for example, the basic command would be something like:
sudo /Applications/Install\ macOS\ Ventura.app/Contents/Resources/createinstallmedia --volume /Volumes/USB --nointeraction
In this example, the volume name is USBTherefore, the path “/Volumes/USB” corresponds to that name. If your volume has a different name, simply replace that part, respecting uppercase and lowercase letters. The parameter --nointeraction This allows the process to not ask anything extra and directly erase the contents of the USB drive.
When you run the command, Terminal will ask you the administrator passwordType it in (you won't see the characters on the screen, that's normal) and press Enter. From there, the tool will begin erasing the volume, copying the installer files, and making it bootable. This process may take several minutes, depending on the speed of your USB drive.
During the process, you'll see messages in Terminal indicating the copying progress and the creation of the bootable media. When it's finished, you'll be able to eject the volume as you would with any external drive.At that point, you'll have a macOS installer ready to use on any compatible Mac.
Identify the correct disk with diskutil list
In some situations, especially when you're going to manipulate disks from Terminal or want to make sure you don't select the wrong drive, it's very useful. Identify the physical disk using the diskutil list command.This shows you a detailed list of all the disks connected to your Mac.
When running in Terminal:
diskutil list
You'll see something similar to an inventory where the following appear numbered disks such as /dev/disk0, /dev/disk1, /dev/disk2, etc.Generally, “disk0” is the main internal disk, and external drives are numbered starting from “disk1”.
In a typical example, you might find output where “disk0” is a GUID scheme with several partitions (EFI, Recovery HD, CoreStorage), “disk1” is an OS X or macOS logical volume, and “disk2” appears as an 8GB USB drive with the FDisk_partition_scheme type and Windows_NTFS label. In that case, the USB drive would be / dev / disk2.
This type of information becomes especially important when you want write a system image directly to the device (for example, using dd) or when you need to check that the USB drive you are going to make bootable is the correct one, so as not to accidentally format the internal disk.
Create a bootable USB drive without using Terminal: BalenaEtcher
If writing commands puts you off, or you simply want a simple visual tool, you can use BalenaEtcher, a multiplatform application (works on macOS, Windows and Linux) designed to burn system images to USB drives or SD cards.
BalenaEtcher stands out because its interface is extremely simple: Choose the image to record, select the USB device and click on FlashThese three steps are used to transfer the image content to the device and prepare it to boot if the image is ready to do so.
To use it on a Mac, you first need to Download BalenaEtcher from its official website (balena.io/etcher). On the site you'll find the macOS version in DMG format. Download the file and, once completed, open it to mount the disk image.
Inside the DMG file, you'll see the application icon. On macOS, this is usually the icon. drag that icon to the Applications folder to install it. This way, you'll have BalenaEtcher available in the Launchpad and you can open it without any problems.
When you launch BalenaEtcher for the first time, macOS may display a security warning (Gatekeeper) indicating that the app is coming from the internet. To avoid problems, the easiest way is to open it by... Right-click on the application and select “Open”so that the system allows you to run it.
Burn a bootable image to a USB drive using BalenaEtcher
Once installed, using BalenaEtcher is almost child's play. The main window displays, from left to right, the options for Select the image, choose the device, and run the Flash process.The process is the same whether you burn an Ubuntu ISO or an installer for another compatible system.
In the first part, click on “Flash from file” (or similar) and select the system image you want to burnIf you're working with macOS, this is usually a prepared image file or an ISO suitable for the process.
Next, in the second step, BalenaEtcher offers the selection of the destination unit. Here, choosing the right unit is crucial. the correct USB drive to avoid overwriting another driveThe program usually detects connected USB drives automatically, but it's always a good idea to check the size and name.
In the third and final step, simply tap on “Flash” to launch the application Start writing the image to the USB drivemacOS will ask for your user password to authorize the operation, and BalenaEtcher will request additional permissions when needed. Confirm and let the process run.
Once the burning process is complete, the USB drive should be ready to boot from the correct computer. You can try it. starting the Mac from that USB drive Following the startup steps that we will see later. If everything has gone well, you should see the installer or system included in the image.
One negative point should be noted: after using BalenaEtcher, USB partitions can become invisible or inaccessible from Finder. In some cases, even mounting from Terminal doesn't allow you to see the contents properly, and Windows may detect the drive as a RAW file system.
Advantages of having a bootable macOS Ventura USB drive
Creating a bootable USB drive of macOS Ventura (or the relevant macOS version) offers several practical advantages, especially if you manage Do you own more than one Mac, or do you often tinker with the system?It's not just a matter of comfort; it can also be a lifesaver when something breaks.
One of the biggest advantages is that You can install macOS on multiple devices without downloading it again. on each one. Simply have the installer on the USB drive and connect it to each compatible Mac to use it as the installation source.
Another important advantage is avoiding download or internet connection problemsIf your internet connection is unstable or slow, downloading a multi-gigabyte system can easily get stuck or fail; with the USB drive already created, that problem disappears and you only have to boot from it.
Having a bootable USB drive also allows you Update or install macOS without needing to be connected to the networkObviously, in some cases the installer may still need the Internet for certain components, but the bulk of the system will already be on the USB drive itself.
Finally, if your Mac is running macOS Ventura (or any other version) won't start or behaves erraticallyA bootable USB drive allows you to boot from that external drive, access Disk Utility, the installer, and other tools to recover or repair the system.
Clean installation of macOS using bootable USB
Once you have the boot installer ready, you can use it to Perform a clean installation, deleting the previous system. and leaving it as if it were freshly installed. This type of installation is usually recommended if you're experiencing unusual errors, have tried several beta versions, or the performance isn't what it should be.
Before you launch, it's vital to have a complete backup of your dataThis can be done either on an external drive using Time Machine, by cloning the internal drive with another tool, or by manually copying the essentials. A clean installation means that the contents of the internal drive will be completely erased.
The general process involves booting the Mac from the bootable USB drive, accessing Disk Utility to erase the internal volume (selecting the appropriate format, such as APFS or Mac OS Plus depending on the computer), and then launch the macOS installation on that empty volume.
When finished, you will go through the initial system wizard, where you will be able to set up your Mac as new or restore data from a backupIf your goal was a completely clean installation, the normal thing to do is to bring only the essential information from the backup and not carry over old configurations.
How to boot your Mac from a bootable USB drive
Creating the installer is half the job; the other half is get the Mac to boot from that USBThe procedure varies slightly depending on whether we are talking about a Mac with an Intel processor or a Mac with Apple Silicon (the M1, M2, etc. chips).
On Intel Macs, the classic process consists of Connect the bootable USB drive to the turned-off computer.Turn it on and hold down the Option (Alt) key immediately after hearing the startup sound or seeing the screen light up. After a few seconds, the boot disk selection screen will appear.
On that screen, your Mac will display the available boot volumes. You'll need to select one. the USB drive containing the installer (usually with a specific installer or external disk icon) and press Enter. From there, the system will boot from the USB drive and you can choose "Install macOS" and follow the instructions.
For Macs with Apple Silicon, the process is different: with the computer turned off, connect the USB cable and hold pressed the power button until you see the boot options on the screen. Then the detected boot volumes will appear, including the USB drive.
From that screen, select again the bootable USB drive Continue to start the installer. Once inside, you can reinstall the system, access Disk Utility, and the rest of the recovery tools.
Recover data if the installation crashes or fails
Problems can arise in the middle of an update or clean installation: power outages, freezes, incompatibilities… and sometimes that translates into lost data or equipment that won't startIf you didn't have a recent backup, the situation becomes more complicated, but there are still options.
There are specialized tools for Mac, such as EaseUS Data Recovery Wizard for MacThese tools allow you to recover files from damaged disks, computers that won't boot, or even from an emptied Trash. The approach usually involves creating a bootable disk with the tool itself and using it on the affected Mac.
The typical workflow would be to install the recovery software in another Mac that does workChoose the option to create a bootable USB drive for your "Mac that won't boot" and let the program prepare a bootable space (for example, 2 GB) on a USB drive. The rest of the USB drive's space can still be used for normal storage.
Next, you boot the damaged Mac from that recovery USB and continue Instructions for scanning the internal disk Searching for recoverable files. It is recommended to restore the data to an external hard drive to avoid overwriting anything on the original volume during the recovery process.
Once you have your important files backed up, you can afford to format the disk and reinstall macOS with more peace of mind. Even so, it's always wiser to have a backup beforehand so you're not solely reliant on recovery tools.
Create bootable drives for older versions: Tiger, Leopard, and classic computers
When we talk about older machines, like a iBook G4 with MacOS Tiger or LeopardThe situation changes slightly. These systems usually boot better from original DVDs or adapted images, and not all of them reliably recognize a USB drive as a boot disk.
In many cases, even if you try to create a bootable USB drive from a modern Mac, When I enter the iBook's boot disk menu, that USB drive does not appear.This is a fairly common firmware limitation in Macs from the mid-2000s, especially on computers designed for installations from CD or DVD.
If you have an original Mac OS X 10.5 disc and the system gives you errors such as "cannot be installed on this computer", it may mean that The disc does not exactly match the model (for example, a DVD supplied with a different Mac) or that there are hardware or partitioning problems on the iBook's internal disk.
In those types of scenarios, it tends to be more reliable use the original optical media or resort to methods specific to those models, such as booting from FireWire (in target disk mode) or from a compatible external optical drive. Modern USB methods are not always recognized by older firmware.
If you still decide to work from a modern Mac, you'll need to identify the correct drives with "diskutil list" and prepare the images with older or adapted utilities, but you have to assume that the computers of that era They're not as flexible with USB booting as modern Macs..
In short, creating a bootable drive from macOS combines several elements: A complete installer, a prepared external drive, Terminal or tools like BalenaEtcher, and a little care when booting the Mac from the USB.By following the steps carefully, you'll have your own "lifeline" for installing, reinstalling, or repairing macOS whenever you need it, and you'll avoid more than one scare when the system decides to fail at the worst possible moment.
