How to Set the Primary Display on macOS Tahoe, Sequoia, or Sonoma

Using multiple displays with a Mac is a very common setup, whether that’s using a larger external monitor with a laptop, or running a multi-display desktop setup. It’s well known that large screens and external displays can really boost some peoples productivity, and one way to further improve your multi-screen Mac setup is by choosing which of your displays is the “primary display”. For the unfamiliar, the Primary Display in MacOS is the screen that shows the Dock, menu bar, desktop icons, and where apps and alerts open to by default, and yes, this can be changed in multi-monitor Mac configurations.

MacOS makes it pretty easy to adjust the Primary Display, but it’s also a fairly subtle feature that is easy to overlook, especially in modern MacOS versions like MacOS Tahoe, MacOS Sequoia, and macOS Sonoma.

How to Change the Primary Display on macOS Tahoe, Sequoia, Sonoma

You must have at least two displays in active current use on the Mac to be able to change the primary display. This could be any MacBook laptop connected to an external screen, or any other multi-monitor Mac setup.

1. Connect the external display(s) to the Mac and make sure they are powered on, if you have not done so already
2. From the  Apple menu go to “System Settings”
3. Go to “Displays”
4. Click on the “Arrange” option to view display layouts
5. Notice the small slim white menu bar shown at the top of one of the displays, this is what defines and sets the Primary Display, therefor you need to click and drag the white menu bar to the display you want to set as the Primary Display
6. The change takes effect immediately, you will see the screens refresh and the Dock, Menu Bar, desktop icons, and any new alerts or opening apps will now default to opening on the set Primary Display

There you go, you have now changed the Primary Display on your Mac.

Once you set a primary display, the preference will stay put every time you connect MacOS to that particular external display. Connecting the Mac to a new external display usually requires you to set the Primary Display again, however.

This works the same on all modern versions of MacOS for all Macs with multiple displays, whether you’re using a MacBook Air, MacBook Pro, MacBook Neo, or MacBook laptop, iMac, Mac mini, Mac Pro, Mac Studio, or any other Mac.

The setting to adjust is obviously pretty subtle, and there’s no clear indicator that the white menu bar is movable or would be used to change or set the primary display, so it’s understandable how so many Mac users overlook this feature.

How to Identify the Primary Display Set on a Mac

The simplest way to identify which Mac display is set as the Primary Display is to look for where the Dock, menu bar, and desktop icons are located, as those are always default set to the primary display.

You can also open a new app, which will default to opening on the primary display, or trigger a system alert, which also gets sent to the primary display by default.

Can you move the Dock between Mac screens?

Yes, you can swipe down to the bottom of the screen you wish to show the Dock on, and it will relocate to that screen, even if it is not set as the Primary Display.

Remember, the Dock defaults to showing on whatever screen the Primary Display is set to.

Yes, MacBook laptops can use a different Primary Display when connected to external screens

If you use a MacBook Air, MacBook Pro, MacBook Neo, or MacBook, you can set an external display as your Primary Display, but when you disconnect the display from the Mac laptop, the internal laptop screen will automatically set itself as the primary display again.

This is intentional behavior, and makes switching between multi-monitor setups and laptop use extra easy and convenient.

What about setting the primary display on older Macs and in older MacOS versions?

Note that if you have an older version of MacOS, you can also set the primary display using a similar trick but the location within settings and how to access it, is different, as covered here.

Much of the change is due to the transition from System Preferences to System Settings, but the behavior with moving the white menu bar to set the primary display remains the same.

Why set or change the Primary Display on a Mac?

For Mac users with multiple screen setups, as is very common in the workforce and with home office setups, setting a primary display can be beneficial to your workflow.

For example, one very common scenario is setting a large external display as the Primary Screen when the Mac is a MacBook Pro laptop with a smaller built-in display. This makes the larger external monitor the primary workspace to engage with. This setup then places the smaller laptop screen as the secondary display panel, which many users will place auxiliary tasks on, like Slack, Messages, Zoom, Notes, Spotify, Apple Music, etc. You can see this with the Messages app on the MacBook display in the image at the top of this article, which is a color variant of this cool setup found on Unsplash, where you will also notice the menu bar is on the primary external display, but not showing on the internal MacBook Pro display.

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Do you use multiple monitors and multiple externals displays with your Mac setup? Do you change the Primary Display to something of your choice to better suit your setup? Did you even know this was possible? Share your thoughts and opinions in the comments.