How to install macOS 27 Golden Gate on another partition

In this step-by-step tutorial, we show you how to download and install macOS Golden Gate (currently in beta) on a second partition of your Mac.

This ensures your current macOS setup stays untouched and as it is, and the Golden Gate beta installation is totally separate. As a result, you will have two different versions of macOS on the same computer.

We have already explained the whole process in our previous guides on installing macOS Tahoe and macOS Sequoia on different partitions. See those as well for reference and screenshots if you get stuck.

Note: Make sure you have an Apple silicon (M1, M2, M3, M4, or M5) Mac, as macOS Golden Gate drops support for Intel-based Macs (full list of compatible Macs here).

Step 1: Create a second partition on your Mac’s drive

Even though we use the word ‘partition’ for simplicity, you’ll actually be creating a new volume on your Mac’s internal disk. Here’s how.

1) Open the built-in Apple Disk Utility app on your Mac from the Finder Applications folder.

2) Select your Mac’s internal drive from the left side and then click the plus Volume button (+) at the top, as shown in the screenshot below.

3) Give this disk a name. I am calling it GoldenGate. Then, name sure the APFS format is selected and click Add. It’s best to leave Size Options untouched.

4) Click Done once this new volume is successfully created.

Step 2: Download macOS 27 Golden Gate installer

macOS Golden Gate is currently in the developer beta stage.

Therefore, it’s best to download the full and official macOS Golden Gate installer directly from this Apple link (thanks to Mr. Macintosh, as always).

You can also download it via Terminal if your Mac is already enrolled in the developer beta program (System Settings > General > Software Update > ⓘ next to Beta Updates > macOS 27 Golden Gate Developer Beta for Beta Updates).

For the purpose of this tutorial, we’re using the direct Apple link method, as it’s simpler and user-friendly.

Once the massive 18 GB file has been downloaded, proceed to Step 3 below.

Step 3: Install macOS 27 on the second partition

1) Go to your Mac’s Downloads folder and double-click the InstallAssistant.pkg file to open it.

2) You’ll now see the ‘Install InstallAssistant’ window. Click Continue.

3) Click Install (you don’t have to change the install location).

4) You should soon see the ‘The installation was successful’ screen. Click Close. You can choose to keep or delete the 18 GB macOS 27 installer file, as its work is already done.

5) Now, open Finder and go to the Applications folder. If you’re on macOS Sequoia or earlier, you can also open Launchpad. Look for the Install macOS 27 Beta.app there as shown in the screenshot below, and double-click to open it.

6) Click Continue on the macOS 27 installer screen and agree to the terms and conditions if you do.

7) Click the Show All Disks button.

8) Select the GoldenGate disk you created earlier in Step 1 and hit Continue.

9) Select a user account (likely yours) and hit Install. Then, enter your Mac’s admin password and click Unlock.

10) macOS 27 Golden Gate will start installing. It will take a while, as shown on your computer screen. It’d be best if you didn’t do anything resource-intensive on your Mac and let this process complete peacefully.

11) Once the macOS 27 installation is complete, click the Restart button. Your Mac may boot up and show the Apple logo  on the screen more than once. Just sit patiently.

Step 4: Set up macOS 27 like you do a new Mac

1) Once the installation is done, you’ll see the ‘Select your country or region‘ screen that you get when you boot up a new Mac for the first time. Select your country, then choose to set up this macOS 27 Golden Gate installation as a new machine or transfer data from another Mac, PC, iPhone, etc.

2) Create a new account for this macOS installation or create one based on your current account in your existing macOS installation. In both cases, you should be prompted to enter your current account’s login password (the same one you have been using all this time to log in to your account on the old macOS installation).

3) Then sign in with your Apple Account or set it up later in System Settings.

4) Go through all the setup steps until you see the welcome screen. You have now successfully installed macOS Golden Gate on a separate partition. Install your apps, configure settings, and take it for a spin.

Step 5: Boot your Mac into macOS 27 or the other installation

You now have two macOS versions installed on the same Mac. So, how do you select which one to boot into?

The first option is to press and hold the power button on your Mac, then select a disk to boot from.

The second method is more user-friendly:

1) Press the Mac’s power button normally and let it boot into your current default startup disk (it could be the new macOS 27 build or your old one, like macOS Tahoe).

2) Once you’re in, go to System Settings > General > Startup Disk. Select the other disk, click Unlock, enter its admin password (the same one you use to log in), and hit Restart.

3) Your Mac will boot into the chosen disk and also remember your preference. So, next time you press the power button, your Mac will automatically boot into this chosen macOS installation.

Happy using macOS Golden Gate!

Also, check out: How to get the new Siri AI on iPhone, iPad, and Mac

Source link: https://www.idownloadblog.com/2026/06/16/install-macos-27-on-partition/