Fernando Silva of 9to5Mac came up with a clever workaround to have ‘clamshell mode’ in iPadOS 17 when an iPad is connected to an external display. The catch: it doesn’t really turn off the iPad’s built-in display.
Now before readers start spamming the comments, this is not true clamshell mode. True clamshell mode kills the screen of the host computer and moves everything from that display to the external monitor. This will not do that. But this workaround will allow you to close your iPad Pro, connect a Bluetooth keyboard and mouse, and still be able to use Stage Manager on an external display.
Essentially, the method involves disabling the ‘Lock / Unlock’ toggle in Settings ⇾ Display & Brightness that controls whether the iPad’s screen should lock when a cover is closed on top of it. This has been the iPad’s default behavior since the iPad 2 and the debut of the Smart Cover, and it still applies to the latest iPad Pro and Magic Keyboard: when the cover is closed, the iPad gets automatically locked. However, this setting can be disabled, and if you do, then sure: you could close an iPad Pro and continue using iPadOS on the external display without seeing the iPad’s built-in display. Except the iPad’s display is always on behind the scenes, which is not ideal.1
Still: if we’re supposed to accept this workaround as the only way to fake ‘clamshell mode’ in iPadOS 17, I would suggest some additions to improve the experience.