Anything that has at least 16 GB of free space.

You can use an external hard drive, an SSD or a USB stick. What should I use as a bootable installer? So, if you don’t have an internet connection or it’s very slow, you need an alternative.

However, that means re-downloading the installer. Normally, if you need to reinstall macOS, you can just boot from the recovery partition and do it from there.

It’s good protection against a catastrophe striking your Mac’s startup disk, especially if you don’t have a stable internet connection.

You may want to clean install Catalina, in which case you’ll completely wipe your startup disk and will need to boot from an external drive to do that.

If you have more than one Mac, it allows you to install Catalina on all your other Macs without having to download it from the App Store each time.

There are a number of reasons for creating a bootable USB Mac installer. Why do I need a bootable installer for macOS Catalina? That way, if anything goes badly wrong with your Mac, you’ll be able to boot from the installer and get going again quickly. But whichever camp you’re in, it’s a good idea to create a bootable installer for macOS Catalina. You may have already taken the plunge and installed it, or maybe you’re waiting to see how it settles down before you install it. In some ways, it’s like having a completely new computer. MacOS Catalina is a hugely exciting upgrade for the Mac. But to help you do it all by yourself, we’ve gathered our best ideas and solutions below.įeatures described in this article refer to the MacPaw site version of CleanMyMac X. So here's a tip for you: Download CleanMyMac to quickly solve some of the issues mentioned in this article.

How to make a bootable usb os x 10.6.3