The iPhone Duo comes out tomorrow but, given the strong pre-order demand, it is already looking to be a smash hit. And we are all expecting Apple to follow up with a second-generation model next fall, which means the company has to be already working on the next-gen hardware.

On his Power On podcast, Mark Gurman reports that iPhone Duo 2 prototypes inside Apple include Face ID, with the Face ID sensor being integrated beneath the display on the outer screen.

The shift from Face ID to Touch ID on this phone was one of the biggest complaints raised by early iPhone Duo reviewers. 9to5Mac’s Chance Miller called it “the hardest thing to get used to” with the new foldable.

For the first-gen iPhone Duo, fitting Face ID inside the super-thin enclosure seemed to be the blocker. But Apple has been working on making Face ID smaller and less obtrusive, as seen with the under-display IR camera on the iPhone 18 Pro.

With iPhone Duo 2 and the twentieth anniversary iPhone Pro, we may see another evolution where both the IR camera and the flood illuminator go behind the screen, allowing the bezel or Dynamic Island cutout to be even smaller still.

Obviously, that just because they are testing the technology on iPhone Duo prototypes right now, it is not guaranteed that it will ship in next year’s revision. But it seems like that is what Apple is aiming for, so customers can probably expect it either next year or as part of the iPhone Duo 3, if development slips.

On the same episode, Gurman also says that employees have been exploring ways to also bring the Action button to a next-generation model of iPhone Duo as well, although he seems less confident about this.

It’s also unclear if Apple would remove the Touch ID sensor from the power button if it adds Face ID to the device, or whether it would keep both methods of biometrics allowing users to authenticate whether they are looking at the inner or outer display.

My favorite Apple gear and accessories 

• AirPods 5: great noise cancellation earbuds and new lower price
• SwitchBot Wallet Tracker: never lose your wallet again with this Find My-enabled tracker
• Eve Outdoor Cam: Reliable and sleek HomeKit camera with integrated floodlight 

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