With the release of El Capitan, Apple took the opportunity to give Disk Utility a facelift. You can still use the software to format a startup drive—it’s similar to the steps in the previous version.

1. El Capitan Boot Drive
2. El Capitan Bootable Installer
3. El Capitan Boot Disk

This how-to goes through the steps of formatting a startup drive using Disk Utility 15 in El Capitan. If you’re using an older version of Disk Utility, the steps are here.

When the OS X El Capitan and Unibeast downloaded, open Disk Utility and click Erase then enter a. At this year's WWDC, Apple announced the next iteration of OS X, version 10.11. Dubbed 'El Capitan' after the famous landmass in Yosemite National Park, this version of OS X builds upon the roots. We've created El Capitan USB stick from both Yosemite and El Capitan, but your experience with other versions may vary. An 8GB or larger USB flash drive or an 8GB or larger partition on some other.

1. Connect your drive

To format an external storage device, connect it to one of the ports on your Mac. Turn the drive on, and make sure it appears in the Finder.

If you’ve already installed El Capitan and you want to format you Mac’s internal drive, you can boot into Recovery Mode to format the drive. To boot into Recovery mode, start up your Mac and hold down Command-R. You should see a window labeled OS X Utilities. (Note: if you format your Mac’s internal drive, this will erase all of the data on the drive, including your apps, file, and the operating system.)

2. Open Disk Utility

You’ll use OS X’s Disk Utility app to format the drive. Locate Disk Utility in Applications > Utilities and open it.

If you booted into Recovery mode, select Disk Utility at the bottom of the window (see below).

3. Select the storage device in Disk Utility

Disk Utility’s left pane shows the storage devices connected to your Mac. Underneath each device are the drive’s partitions. Select the device you want to format. Then click the Erase button at the top.

If the Erase button is dimmed, it means the drive you want to format is in use and you need to boot off another drive or into Recovery mode, which was described in step 1.

4. Name and Format

A dialog box will appear. You need to enter a name for your storage device.

Click the pop-up menu for Format, and you can select one of the formats. The default selection is OS X Extended (Journaled); if you want a layer of security, you can go with OS X Extended (Journaled, Encrypted), which will encrypt your storage device. (If you don’t see the Encrypted options, that’s probably because the drive you are formatting is currently not using a GUID Partition Map. Select OS X Extended (Journaled), proceed to step 5, and then come back to step 4, repeating the step but with an Encrypted option selected.)

The “Case-sensitive” formats allow for file names with capital letters to be different from lowercase letters. So, for example, three files named FILE, File, and file can exist in the same folder. You probably don’t need to use a Case-sensitive format.

MS-DOS and ExFat are PC formats. Since we’re formatting a Mac startup drive, you can ignore these two.

El Capitan Boot Drive

5. Scheme

There’s a third selection you need to make called Scheme. For an Intel-based Mac running El Capitan, select GUID Partition Map. There are two other options you can ignore: Master Boot Record is for Windows, and Apple Partition Map is for PowerPC-based Macs (remember those?).

When you click Erase, Disk Utility will erase the data, reformat the storage device, and mount the drive on your desktop. Click Erase when you’re ready to proceed. After a few minutes, your storage device will be ready for you to install El Capitan.

These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.

What you need to create a bootable installer

• A USB flash drive or other secondary volume formatted as Mac OS Extended, with at least 14GB of available storage
• A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan

Download macOS

El Capitan Bootable Installer

• Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
  These download to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
• Download: OS X El Capitan
  This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.

Use the 'createinstallmedia' command in Terminal

1. Connect the USB flash drive or other volume that you're using for the bootable installer.
2. Open Terminal, which is in the Utilities folder of your Applications folder.
3. Type or paste one of the following commands in Terminal. These assume that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.

El Capitan Boot Disk

Big Sur:*

Catalina:*

Mojave:*

High Sierra:*

El Capitan:

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument and installer path, similar to the way this is done in the command for El Capitan.

After typing the command:

1. Press Return to enter the command.
2. When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
3. When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
4. After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
5. When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.
   

Use the bootable installer

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

1. Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
2. Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes.
3. Select the volume containing the bootable installer, then click Continue.
4. When the macOS installer opens, follow the onscreen instructions.

Intel processor

1. Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
2. Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
3. Release the Option key when you see a dark screen showing your bootable volumes.
4. Select the volume containing the bootable installer. Then click the up arrow or press Return.
   If you can't start up from the bootable installer, make sure that the External Boot setting in Startup Security Utility is set to allow booting from external media.
5. Choose your language, if prompted.
6. Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.

Learn more

A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.

For information about the createinstallmedia command and the arguments you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal: