[Editor's note: This article is part of our series of articles on installing and upgrading to Mavericks.]

Mavericks (OS X 10.9) doesn’t ship on a disc. Instead, it’s available only as an installer app downloadable from the Mac App Store, and that installer doesn’t require a bootable installation disc. But there are a good number of reasons you might want a bootable Mavericks installer on an external hard drive or a thumb drive (USB stick).

For example, if you want to install Mavericks on multiple Macs, using a bootable install drive can be more convenient than downloading or copying the entire installer to each computer. Also, if your Mac is experiencing problems, a bootable install drive makes a handy emergency disk. (The OS X Recovery feature is a big help here, but not all Macs have it—and if your Mac’s drive is itself having trouble, recovery mode may not even be available. Also, if you need to reinstall Mavericks, recovery mode requires you to download the entire 5.3GB installer again.) Finally, if you need to install Mavericks over Leopard—assuming you have the license to do so—a bootable install drive makes that process easier.

Thankfully, it’s not too difficult to create a bootable install drive from the Mavericks installer. I show you how, below.

If your Mac came preinstalled with Mavericks

If you own Mavericks only because you bought a Mac that shipped with Mavericks preinstalled—in other words, you never purchased the OS from the Mac App Store—use our instructions for creating a bootable Mavericks install drive for newer Macs, instead of the instructions here.

Get the latest version of the Mavericks installer

Before you make a bootable install drive, you should make sure you have the latest version of the Mavericks installer. What? You didn’t even realize that there are different versions of the installer? It turns out that when you download an OS X installer from the Mac App Store, that copy of the installer contains whatever version of OS X was available at the time of download. For example, if you downloaded OS X 10.9 on the day Mavericks was released, you downloaded the 10.9.0 installer. A bootable install drive you create from that installer will install OS X 10.9.0.

However, Apple regularly updates the OS X installers it makes available for download from the Mac App Store. For example, when the inevitable 10.9.1 update is released, a few days later the Mac App Store will begin providing an updated Mavericks installer that installs 10.9.1 right off the bat. Using the latest installer for your bootable install drive is convenient, because it means that if you ever need to reinstall Mavericks, you won’t have to install 10.9.0 and then immediately install the latest big update.

Obviously, then, you want to create your bootable install drive using the latest version of the Mavericks installer. However, unlike with other Mac App Store-purchased software, the Mac App Store does not update the copy of the Mavericks installer app sitting on your hard drive. If you’ve got an older version of the installer and you want the latest version, you must delete your current copy of the installer and then redownload the Mavericks installer from the Mac App Store. (If the Mac App Store won’t let you redownload the installer, quit the Mac App Store app, relaunch it, and then Option+click the Purchases tab in the toolbar; that should show the Download button next to Mavericks in the Purchases list.)

Similarly, any bootable Mavericks install drive you create will not be updated to the latest installer version automatically. So if you create an install drive and later download an updated version of the Mavericks installer, you’ll want to erase that install drive and recreate it using the new installer.

The Mac App Store displays details about the current version of the Mavericks installer.

How do you know if you have the newest version of the Mavericks installer? The easiest approach is to look at the Information box on the Mavericks page on the Mac App Store—specifically, check the date next to Updated (or Released, as the case may be immediately after the initial release). Then locate your downloaded copy of the Mavericks installer in the Finder, choose File -> Get Info, and look at the date next to Modified. If the Mac App Store date is newer than the Modified date on your copy of the installer, you need to redownload the installer to get the latest version. (The version listed in the Mac App Store’s Information box is the version of OS X you’ll get if you download the latest installer.)

Note: As I explained in our main Mavericks-installation article, if you leave the Mavericks installer in its default location in the Applications folder when you install OS X 10.9, the installer will be deleted automatically after the installation finishes. So if you plan to use that installer on other Macs, or—in this case—to create a bootable drive, be sure to copy the installer to another drive, or at least move it out of the Applications folder, before you install. If you don't, you'll have to redownload the installer from the Mac App Store before you can create a bootable install drive.

A note on installer compatibility

The initial Mac App Store version of Mavericks will boot only those Macs released prior to Mavericks’s debut; Macs released after Mavericks’s debut ship with a newer version of OS X 10.9 preinstalled. This means that if you made a bootable install drive immediately after Mavericks was released, and then later bought a new Mac, your install drive won’t boot that Mac (though it will boot any older Macs you own).

However, as explained above, Apple regularly updates the OS X installer on the Mac App Store so that it installs the latest version of OS X 10.9. If you create a new bootable installer using the first major update to Mavericks after your Mac was released, that drive should be able to boot all your Macs.

What about an optical disc? You may have noticed that I didn’t mention making a bootable install disc (DVD or CD). Though you can do it, I don’t recommend it. More and more Macs ship without a built-in optical drive; booting and installing from a DVD is very slow; and 8GB flash drives can be found for $10 or less. All of this means that there’s little reason to opt for a DVD anymore. In addition, whenever an update to OS X is released, you can easily erase your bootable USB stick or external hard drive and update it to contain the latest OS X installer; with a DVD, you have to toss the disc in the trash and start over, which is both a hassle and bad for the environment.

All that said, if you're absolutely convinced that you need an optical disc, Thomas Brand explains how to create a Mavericks recovery CD. The resulting disc won't contain the full installer; rather, it's a CD version of OS X Recovery. This means that when you install Mavericks using the disc, the installer needs to download roughly 5GB of installer data on the fly—which means that installation will be even slower.

Create the Mavericks install drive: The options

There are three ways you can create a bootable OS X install drive: using a new feature, called createinstallmedia, built into the Mavericks installer itself; using Disk Utility; or using the third-party utility DiskMaker X, which, despite its name, also works under Mavericks. (For OS X 10.7 and 10.8, you also had the option of using the third-party utility Carbon Copy Cloner. However, because of changes in Mavericks, the developer of Carbon Copy Cloner has removed this feature. I’ll update this article if Carbon Copy Cloner becomes an option again.)

Using the new Mavericks feature for creating a bootable drive, createinstallmedia, is the easiest method, and it’s the one that I recommend most people try first. However, it doesn’t work under Snow Leopard—just Lion or later. DiskMaker X is the next-easiest method, but I’ve experienced the occasional failure with it. (DiskMaker X also doesn’t work under Snow Leopard.) The Disk Utility method is very reliable, and it works under Snow Leopard, Lion, Mountain Lion, and Mavericks.

Note: There’s one significant difference between the three methods that you should be aware of. Based on my testing, if the drive onto which you’re installing Mavericks doesn’t already have a Recovery HD partition, a bootable installer drive made using createinstallmedia or DiskMaker X (which uses createinstallmedia under the hood) can create that partition during the 10.9-install process. A bootable Mavericks installer drive made using the Disk Utility procedure will not. You can determine whether or not your Mac has a Recovery HD partition using the instructions in our article on recovery mode.

Whichever method you use, you need a Mac-formatted drive (a hard drive, solid-state drive [SSD], thumb drive, or USB stick) that’s big enough to hold the installer and all its data—I recommend at least an 8GB flash drive, though anything larger than roughly 5.5GB should work. That drive must also be formatted with a GUID Partition Table. Follow this tutorial to properly format the drive.

Option 1: Use createinstallmedia

Hidden inside the Mavericks installer is a Unix program called createinstallmedia, provided by Apple for creating a bootable Mavericks installer. If you’re comfortable using Terminal, it’s a relatively simple tool to use. The program assumes your account has administrator privileges.

Note: This method does not work in Snow Leopard. It works only in Lion, Mountain Lion, or Mavericks. (The resulting installer drive will let you install Mavericks over Snow Leopard, but you can’t create the installer drive while booted into Snow Leopard.) If you need to create a Mavericks install drive while booted into Snow Leopard, you should use the Disk Utility instructions, below.

Download the Mavericks installer from the Mac App Store and make sure it’s in your main Applications folder. (This means that if you followed my advice to move the installer out of your Applications folder, you’ll have to move it back, at least temporarily. The Terminal command I’m using here assumes the installer is in its default location.) Connect to your Mac a properly formatted 8GB (or larger) drive. Rename the drive to Untitled . (The Terminal command used here assumes the drive is named Untitled.) Select the text of this Terminal command and copy it: sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction Launch Terminal (in /Applications/Utilities). Paste the copied command into Terminal and press Return. Warning: This step will erase the destination drive or partition, so make sure it doesn’t contain any valuable data. Enter your admin-level account password when prompted. The Terminal window displays the progress of the process, in a very Terminal sort of way, by displaying a textual representation of a progress bar: Erasing Disk: 0%... 10%...20%... and so on. The program then tells you it’s copying the installer files, making the disk bootable, and copying boot files. Wait until you see the text Copy Complete. Done. (see the screenshot below), which could take as long as 20 or 30 minutes, depending on how fast your Mac can copy data to your destination drive.

You now have a bootable Mavericks-install drive. If you’re curious about createinstallmedia, type or paste the following command in Terminal and press Return:

/Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia

The resulting text output shows you the (brief) instructions for using createinstallmedia more generically. (Thanks to a developer on Apple’s Developer Forums for pointing out createinstallmedia a few months ago.)

Using the createinstallmedia command in Terminal

Option 2: Use Disk Utility

You’ll find Disk Utility, a handy app built into OS X, in /Applications/Utilities. Here are the steps for using it to create your installer drive, which are a bit more involved with Mavericks than they were with Mountain Lion and Lion.

Note: As mentioned above, based on my testing, an installer drive created using Disk Utility will not create a Recovery HD partition if your Mac’s drive doesn’t already have one. You can determine whether or not your Mac has a Recovery HD partition using the instructions in our article on recovery mode. If your Mac’s drive is missing the Recovery HD partition, you should use the createinstallmedia instructions, above, as the resulting installer drive will create the missing partition when you install Mavericks.