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Here's how to install macOS 11 Big Sur from scratch

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Check if our Mac is compatible
Backup to Time Machine
Build your own macOS 11 Big Sur installer (recommended)
Download and install directly from the Internet

The launch took a little longer than expected, and the remaining Apple operating systems such as iOS 14, iPadOS 14, watchOS 7 and tvOS 14 were able to be installed a few days ago. In this case, macOS 11 Big Sur was left in the pipeline by Apple's decision and now all users can install it on their Macs.

Not only does the new version of the Mac operating system change the number, macOS 11 has a lot of new features and it is important to update them when you can as the new version greatly improves the version of macOS Catalina. Anyway, now you can install the new operating system so let's see how to install this new Big Sur from scratch , no backups or anything like that.

Check if our Mac is compatible

In this case, the macOS 11 Big Sur version is missing some devices, which is why it is very important to check that our team accepts this latest version of the operating system . You can check this out in the list below. Once we have verified that our Mac is fully compatible with the new version of the operating system, all we have to do is get to work.

  • MacBook 2015 and above
  • MacBook Air 2013 and above
  • MacBook Pro 2013 and above
  • Mac min 2014 and later
  • 2014 and later iMac
  • IMac Pro from 2017 to the current model
  • The Mac Pro in all its versions since 2013

Another detail to consider in this release is the update of the application theme to 64-bit.It is important to check that the apps and other tools we are using are compatible with the new macOS . This point is key to upgrading and installing the new macOS from scratch. If everything is okay, we can follow the steps.

Backup to Time Machine

It's always important, and while we don't need to restore anything later to do the installation from scratch, it's important to make a copy of our documents, photos, files, and others. Have a "backup" of the system This can be of great help in the event of  problems. So don't forget to make a backup in case you need it.

Build your own macOS 11 Big Sur installer (recommended)

Cleaning System Installation It's really easy to perform, but we can't skip a step . You can do the installation from scratch on our Mac in two ways. One of them is to delete everything directly from the terminal or through an internet connection.

In one case we need an external USB or SD card with at least 8 GB  better at 12 GB and in others it is best to have a good fiber optic connection so that the download occurs as quickly as possible. This also depends on the Apple servers and the people who are downloading the new version of macOS 11 Big Sur at the same time. So be patient.

Personally, we recommend using a USB as that way we have the installer in case we want to "use it on other computers" or not. If you can, try to avoid a promotional USB or something similar as these can cause installation problems, although they will work too. It's always better to have a good USB or USB-C disk just in case.

Before starting the installation, we recommend that you read the steps well, if you have never done it before and after reading it several times, start with it. It is important to be clear about what we are going to do. So let's start:

  • First, we need to download macOS 11 Big Sur so that we can access it through the Mac App Store on a Mac that will allow installation. Once downloaded, we will NOT install it. We will leave it downloaded and close the installer
  • Without opening the downloaded file, we connect the USB or external drive and we rename it to BIGSUR
  • Now we write or copy this in Terminal: sudo / Applications / Install \ macOS \ Big \ Sur.app/Contents/Resources/createinstallmedia –volume / Volumes / BIGSUR –nointeraction
  • Remember that BIGSUR is the name of the connected external drive that we pasted earlier and  it is very important to edit the scripts when copying two separate scripts in Terminal. You can use any name
  • It will ask for our password and the contents of the external drive will be deleted. We click "Enter" and the creation of the boot installation program begins, which can take some time.

Right now we have to be patient. As soon as everything ends and without disconnecting the USB port from our Mac, we restart the device and when the «chan» sounds, we press the Option key (Alt) «to select the external memory. We'll look for the macOS Big Sur installer and click on it to install it.

the devices with the T2 chip may require the combination cmd + R to enable booting from an external drive. In this case we have to allow the start after pressing and that's it.

Now all we have to do is wait for the installation process to run automatically on our Mac. Follow the steps and enjoy the new macOS Catalina. It is important to be patient and not be in a rush to do this type of installation from scratch. The process may take a few minutes  So you don't want to run at the time of the installation.

Download and install directly from the Internet


This option is a bit simpler as we only need a network connection to install the new version. It is not recommended, but it can also be useful. This method is to wipe the entire macOS hard drive and force it into recovery mode. For that we have to turn off the Mac and when I reboot we have to press the Option (Alt) + Command (CMD) + R keys.

Once the entire hard drive is removed we will have to click on the  Utilities and in it we will be able to press macOS recovery mode over the internet. This allows the team to quickly download and install macOS 11 Big Sur through the terminal without creating a USB port.

It is possible that this option will install an earlier version, in which case it is best to use the installation option discussed above. This is usually not the case, but there are cases. With that in mind, it can make sense to install directly from a USB port, as we showed earlier.

Once this process is complete, it is recommended that you restart your computer for everything to work properly. In either case, it is important to be clear that it will take time and it is not a few minutes to update, so calm down,  be patient and wait for the process to complete.

On the other hand, it's important to note that this is recommended for installing on a MacBook, leaving the device plugged into the charger to avoid problems, this will be indicated by the system itself when updating. However, if we are going to do the installation from scratch, even if the system does not say so, it is best to connect it to the network to avoid problems.

The best system for us is the one created by the external installer as this way we have a physical option in case we need to install this system on other computers with problems.


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