How to use iPad in portrait with Sidecar with macOS Sequoia

Five years after Apple introduced Sidecar with macOS Catalina, it has given it a much-wanted update. Previously Sidecar would only extend a Mac's display onto an iPad in landscape, regardless of what way around the device was being held or mounted.

There was a fairly contorted workaround that would make it happen with the use of a third-party app. But now with macOS Sequoia 15.1 and iPadOS 18.1, you can just turn on Sidecar and then physically rotate your iPad.

How to turn on Sidecar

1. Open System Settings, Displays
2. Click on the plus underneath the image of your Mac's screen
3. The plus sign is a drop down listing various devices
4. Find your iPad and select it
5. Look for the Use as section that now appears
6. Choose Extended Display from the dropdown that defaults to showing Main Display

The iPad needs to be on, but it will still appear in the list of devices even if it isn't. It's a list of compatible devices associated with the Apple Account in use on the Mac.

With the Mac and iPad on, and Use as set to Extended display, your Mac screen now extends out onto the iPad. There's an arrange button that lets you set whether the iPad is on the right or left of your Mac screen.

This section will show a representation of your two screens side by side. You can only move their position to set each to the left or right of the other.

But if you physically rotate the iPad, the representation of it on the Mac screen rotates to portrait too.

It's simple until it isn't

This new feature has come in with macOS Sequoia 15.1. However, at time of writing, it is not present in the separately produced developer beta for macOS Sequoia 15.2.

This will doubtlessly be resolved before macOS Sequoia 15.2 is released to the public. But at present it is also a little buggy — sometimes it will not allow you to select Extended Display, for instance.

Apple has not confirmed when macOS 15.2 will be publicly released. However, its chief addition to the Mac is Apple Intelligence and Apple has committed to rolling that out over the next few months.