How to Upgrade to OS X Yosemite on a Mac

There's a simple installation method

macOS Yosemite follows the tradition of providing an easy upgrade install as the default installation method. The process can be completed in just a few onscreen steps.

But before you launch the Yosemite installer, you should take a moment to ensure it is the right install option, that your Mac is properly prepped, and that you have all the information you will need at your fingertips.

How to Upgrade Install macOS Yosemite on Your Mac

OS X Yosemite Desktop
Coyote Moon, Inc.

Yosemite doesn't require any new or specialized hardware to work on most Macs. If your Mac can run macOS Mavericks, it should have no difficulty with Yosemite.

Once you're sure that your Mac meets the minimum requirements, you're almost ready to proceed, but there are still a few more steps to take.

Back Up, Back Up, Back Up

You're going to be making major changes to your Mac — installing new system files, deleting old ones, applying for new permissions, and resetting preferences. There's a lot that happens behind the curtain of the install wizard. Should something occur during installation, such as a drive failure or power outage, your Mac may fail to restart or be compromised in some permanent way. To limit the risk of losing important data, make sure to back up your existing data before proceeding.

Types of OS X Yosemite Installation Options

Yosemite supports the usual installation options: Upgrade Install, which is what this guide covers, and Clean Install. The Clean Install option has some variants, such as installing on your current startup drive or on a non-startup drive.

  • Upgrade Install: An Upgrade Install will completely remove the existing version of macOS from the startup drive. It will update all needed system files, and update all applications that Apple includes with the OS, such as Mail and Safari. An upgrade install won't make changes to your user data; as a result, your user accounts and any data associated with them will remain. However, when you first run an app, it is likely that your data will be updated to work with the newer version. For that reason, you should not expect to be able to return back to the previous version.
  • Clean Install: A Clean Install will completely delete all data on the target drive and replace it with macOS Yosemite and the default apps that come with it. Selecting the Clean Install option will leave your Mac in a similar condition to the day you got it: no user data, no user accounts, and a setup wizard for creating your first administrator account.

A Clean Install is for starting from scratch. Before you decide to use the Clean Install option, be sure to backup all of your data.

How to Download macOS Yosemite and Start the Upgrade Install

OS X Yosemite Installer
Coyote Moon, Inc.

The first step in installing Yosemite is to check your Mac's startup drive for any problems, including repairing permissions.

Yosemite is available from the Mac App Store and is a free upgrade from macOS Snow Leopard (10.6) or later. If you're running a version of macOS that is older than 10.6, you will need to first purchase Snow Leopard and then install it on your Mac.

Upgrade Install macOS Yosemite

Before proceeding, make sure you have a copy of macOS Yosemite downloaded. You can find and download Yosemite for free from the Apple website.

  1. The download process will most likely deposit the Yosemite Disk Image (.dmg) in the Downloads folder. Once the download is complete, launch the item to begin the installation process and follow the on-screen instructions.

  2. When the Install OS X app opens, select Continue to proceed.

  3. The Yosemite license agreement will appear. Select Agree.

  4. A window will appear asking you to confirm that you have read the license agreement. Select Agree.

  5. You'll be presented with your Mac's startup drive as the install destination for macOS Yosemite. If this is correct, select Install. You can select Show all Disks to select a different drive location.

    If you don't wish to overwrite your startup drive with the new OS, or any of the available drives, select Quit Install OS X from the Install OS X menu.

  6. You'll be asked for the administrator password. Enter the password and select OK. The installer will begin by writing needed files to the startup drive. This process can take a few minutes. When it's complete, your Mac will restart.

  7. After the restart, your Mac will display a gray screen with a progress bar. Eventually, the display will change to show an install window, with a progress bar and a time estimate.

  8. Once the progress bar completes, your Mac will restart again, and you'll be taken to the login screen.

Yosemite has been installed and you're ready to start the setup process, where you configure the OS to match your preferences.

macOS Yosemite Setup Process

AppleID sign in option for OS X Yosemite
Coyote Moon, Inc.

How to Set up macOS Yosemite

At this point, you've completed the upgrade install process. Your Mac has rebooted and is displaying the login screen.

  1. Enter your account password, then press the Enter or Return on your keyboard.

  2. Yosemite will display the desktop along with a window asking you to log in with your Apple ID. You can skip this process if you wish by select Set Up Later. We recommend signing in because it will make the setup process move along faster. Once you've entered your Apple ID, select Continue.

  3. A drop-down window will request permission to allow this Mac to be used with the Find My Mac service. Select About Find My Mac to view information about the service, Not Now to disable the service (you can turn it back on later), or Allow to enable the Find My Mac service.

  4. The Terms and Conditions window will open, asking you to agree to the license terms for macOS, Apple's Privacy Policy, iCloud, and the Game Center. You can review each license by select More. If you accept the terms of all the licenses, select Agree.

  5. A drop-down window will ask if you agree to the terms. Select Agree.

  6. The next step asks if you wish to set up iCloud Keychain. You can select Set Up Later if you'd like to defer the process, then select Continue.

  7. The Yosemite setup window will display a list of software that is incompatible with the new version of macOS. Any application listed is automatically moved to the Incompatible Software Folder, located at the root of your startup drive (/[startup drive name]/Incompatible Software/). Select Continue.

  8. The macOS installer will complete the setup process. This usually takes a few minutes, after which the desktop will appear, ready for you to use.

Now that macOS Yosemite is installed, take a look around. Check out Safari, which is much faster than previous versions. You may find that a few of your preference settings were reset during the upgrade install. If you bring up System Preferences, you can go through the preference panes and set your Mac up as you wish.