Every year Apple releases a major update for macOS that introduces new features and improvements for your Mac. These updates are completely free, and you can even sign up for the public beta for early access.
If you have a few Mac computers in your home or office, you probably don't want to spend hours downloading the large macOS installer multiple times. However, Apple doesn't save the macOS installer in an obvious location, making it difficult to use the same file again.
Do not worry; We'll show you how to make better use of the macOS installer.
Why should I save the macOS installer?
Since most users only need to use it once, the macOS installer will automatically delete itself after you use it. This only happens if you save the installer before running the update.
Unlike most minor updates, the macOS installer comes with an entire operating system for your Mac. That said, it can be huge, sometimes up to 8GB or more.
If you want to use the macOS installer multiple times and don't save it first, you'll have to download it again on each Mac you update. This takes a long time and uses your internet bandwidth as each download can take two hours or more.
This can be a problem if there are many Mac computers in your home or office.
If you download the latest macOS update as soon as Apple makes it available, download times will likely be even slower while Apple's servers will struggle to keep up with initial demand.
You can save yourself a lot of hassle by saving the macOS installer after the first download. That way, you can use the same macOS installer to update as many Mac computers as you need without multiple downloads.
You can even use the installer to install macOS on a Windows PC.
Save the macOS installer to create a bootable USB stick
The macOS installer file can also be helpful if you run into a problem with your Mac in the future. If you want to "restart" and reinstall macOS, you will need the macOS installer.
If you want to keep the macOS installer for troubleshooting purposes, your best bet is to get a replacement flash drive and turn it into a bootable USB stick instead. That way, you can use the bootable USB stick to reinstall macOS even if your Mac won't start anymore.
To create a bootable USB installer, you'll need to start your Mac in recovery mode and use a special terminal command. This is more complicated than just wanting to update multiple Macs – instead of fixing them – so we'll stick to the simple workflow below.
Notice: If you have an older Mac that doesn't support the latest version of macOS, be sure to save the appropriate macOS installer for that Mac in case you need to repair it in the future. You can download this file and create a bootable USB stick on any other Mac.
How to download the macOS installer
Although you can download the latest version of macOS from System Preferences on your Mac, it will also start the installation process, which will delete the installer.
Instead, download the macOS installer from the Mac App Store. However, You still need to exit the macOS installer if it starts after the download is complete.
You can find the latest version of the macOS installer by searching for it in the Mac App Store. Older versions of the macOS installer can also be found in the App Store, but they are not displayed during a normal search.
Use these links to find the appropriate macOS installer in the Mac App Store instead:
Download the macOS installer like any other app: click ReceiveEnter your Apple ID password and wait for the download to complete. The installation program will start automatically. So press Cmd + Q. or go to Install macOS> Quit from the menu bar to close it.
Older versions of Mac OS X are no longer available in the Mac App Store. However, you can still download them as disk images directly from Apple's website. Next, open the disk image to find the Mac OS X installers:
Where is the macOS installer located?
Unlike most files, the macOS installer isn't in the Downloads Folder after downloading it. Instead, you can find the macOS installer in your Applications Folder.
The only exception is when you download OS X El Capitan or OS X Yosemite, which will save a disk image to your computer Downloads Folder. Double-click to mount the disk image and find the OS X installer inside.
How to save the macOS installer
The macOS installer will delete itself after you run it. So you need to save a copy first. It's best to keep this copy on an external drive so you can move it to other computers so you can still install macOS from the same file.
To copy it Ctrl-click the macOS installer in your Applications Folder and select Copy. Then open the destination drive or folder and Ctrl-click to Insert.
If you want to run the macOS installer to update a Mac, it's best to make another copy of the installation file in the Applications Folder on this Mac. Your Mac will delete this copy once the macOS installation is complete.
Before you install macOS
Installing a new operating system is a big upgrade, and while most installations go smoothly, there is always a chance that something could go wrong. For this reason, you should always back up your Mac with Time Machine before updating macOS.
There are also other precautions you can take before installing macOS to minimize the risk of problems:
to open Disk utility and run First aid on your startup disk to remove authorization errors.
Open that Apple menu and select About this Mac> Storage to ensure that you have at least 16 GB of free space to install the update.
Make sure your MacBook is plugged in or fully charged before you begin.
The entire installation process typically takes about 30 minutes. You won't be able to use your Mac during this time until it ends up restarting.
If you run into issues, check out our troubleshooting guide for macOS installation errors.
Update your apps after installing macOS
After updating macOS, open the Mac App Store to check for new updates for your apps. You'll need to separately update any apps you installed from outside the App Store, although most will tell you when an update is automatically available.
You should also plug in your Time Machine drive and create a new backup.
The latest version of macOS may not be compatible with all of your favorite apps. This happens from time to time. If you need to find replacement apps, check out our list of the best Mac apps to get started.
The best Mac apps to install on your MacBook or iMac
Welcome to our ultimate list of must-have Mac apps. From email clients to system utilities, from time savers to productivity apps, this page is where you can find the best Mac software you should be using.
About the author
(148 articles published)
Dan writes tutorials and troubleshooting guides to help people get the most out of their technology. Before becoming a writer, he earned a BSc in audio technology, oversaw repairs at an Apple store, and even taught English in China.
More from Dan Helyer
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