Download the El Capitan Installer
Download the El Capitan installer from the Apple website. It is no longer available in the App Store. Once the download is complete, the installer starts automatically. When it does, quit the installer. You need a copy of the El Capitan installer to make a bootable USB.
The El Capitan installer is downloaded to the /Applications folder, with the file name “Install OS X El Capitan.” If you’ve installed El Capitan and want to create a bootable installer, re-download the installer from Apple.
Use Terminal to Create the El Capitan Bootable USB Installer
Follow these steps to create a bootable USB installer of El Capitan in Terminal.
Connect the USB flash drive to your Mac. Give the flash drive an appropriate name. You can do this by double-clicking the device’s name on the desktop and then typing a new name. We suggest calling the drive elcapitaninstaller, but you can use any name you’d like, provided there are no spaces or special characters. If you select a different name, modify the Terminal command below with the flash drive name you chose. Launch Terminal, located in /Applications/Utilities/. In the Terminal window, enter the following command: sudo /Applications/Install\ OS\ X\ El\ Capitan. app/Contents/Resources/createinstallmedia –volume /Volumes/elcapitaninstaller –applicationpath /Applications/Install\ OS\ X\ El\ Capitan. app –nointeraction The command is a single line of text, though your web browser may display it as several lines. If you used the drive name suggested above, you can copy and paste the complete line of text. Press Command+C on your keyboard to copy the command from this page and then paste it into Terminal by pressing Command+V. Coyote Moon, Inc. Input your Apple computer password in the password prompt. Press Return or Enter on your keyboard. This command completely erases the USB flash drive. Terminal executes the createinstallmedia command and displays the status of the procedure. Erasing and copying the files from the OS X El Capitan installer can take some time, depending on how fast the USB flash drive is. Once Terminal completes the command, it displays the line Done and then shows the Terminal prompt waiting for a new command. You can now quit Terminal.
The bootable El Capitan installer has been created on the flash drive. You can use this bootable installer to perform any of the supported installation types, including an upgrade install or a clean install. You can also use it as a bootable troubleshooting tool that includes an assortment of apps, including Disk Utility and Terminal.
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia –volume /Volumes/elcapitaninstaller –applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app –nointeraction
The command is a single line of text, though your web browser may display it as several lines. If you used the drive name suggested above, you can copy and paste the complete line of text.
Why Make a Bootable USB Installer
A bootable installer for OS X El Capitan is a good idea, even if your plan is to perform an upgrade install. Having your own copy of El Capitan on a separate device ensures that you’ll always be able to install or reinstall the OS X. It also helps in performing basic troubleshooting tasks, even if you have no connection to the internet or access to the Mac App Store.
What You Need
A Mac that meets the OS X El Capitan minimum requirements. A 16 GB or larger USB flash drive. The El Capitan installer file downloaded from Apple but prevented from completing the installation.
