I Tested the iPhone Duo. Here’s What I Thought.

INEVITABLY, EVEN THE coolest, most unique tech gadget becomes a day-to-day object. That’s the goal, at least. You want to be so familiar with your devices that they become second nature to use, an accustomed shape you can grasp for in the dark or pull out of your pocket and handle without a second thought. If you never get there, you’re not actually using it enough to be worth the investment.

For the first day or two out of my time testing the iPhone Duo, Apple’s debut foldable phone, I doubted I would ever get to that point of comfort. The Duo felt so different than the iPhone 18 Pro Max I had been using for the last month—and from every other iPhone since my first, a 5S in 2013. Reaching for the Duo with its squat dimensions felt awkward, the outer display was harder to scan at a glance, and I didn’t feel compelled to unfold and use the inner displays much at all. Was all this phone even useful?

But at some point on day three, something clicked. I stopped automatically holding the phone up to unlock it with my face (the Duo brings back Apple’s fingerprint Touch ID, more on that in a bit). I flipped out the big screen unconsciously to switch through my apps. I still had reservations about exactly how useful this was compared to a slab-style smartphone, but it felt less like a novelty and more like something I could depend on.

All that led to one of the most engaging test periods I’ve had in my decade reviewing tech. The iPhone Duo really made me think about more than just its specs, camera, and place in the larger Apple ecosystem; I was reconsidering how and why I use smartphones.

The iPhone Duo’s Design

THE FOLDABLE FORM factor isn’t an Apple innovation. While there were plenty of clamshell devices back in the aughts in the days before smartphones (shout out to the LG Voyager), mainstream, modern foldables kicked off in 2019 when Samsung entered the market. Google has been in the game since 2023. Apple, as it often does, stayed out of the space until it was good and ready to bring a polished device to market.

I’ve not used any of the other foldable phones as my daily handheld, so I won’t compare them at length. What I will say is that compared to my brief experience with the other devices, Apple’s design is robust. The Duo is made of titanium; it’s substantial to hold and carry without being too hefty. Its screens aren’t as big as some other models (the outer display, which I used the most, is 5.4 inches, while the fully extended size is 7.6 inches), but the hinge—the feature that the Duo really depends on to function properly—does exactly what it’s supposed to do.

That mechanism is made out of over 100 pieces, with a 3D-printed cover. Opening and closing the phone is oddly satisfying, with an audible snick when it extends to its full size and a snap when it closes (with a little help from a magnetic array to keep it shut).

The inside display has a “nano-textured cover layer,” which Apple says is stiffer than other materials typically used in the industry. In practice, this gives the inner screens a matte look and feel, which is smooth to the touch. And when the Duo is open, the crease is completely imperceptible straight on. I can sometimes spot it when I look from an angle and the display is dark, but how often will I be craning my neck to do that during normal use?

Slightly more perceptible is the FaceTime Camera, hidden beneath the display. It’s a small circle on the screen that’s visible when the device is inactive, then almost obscured by color. Once I got used to looking at the layout, I stopped clocking it entirely.

The hinge doesn’t just keep the Duo fully open or shut. The device can be oriented in a range of positions beyond just vertical or landscape. Hold it up like a book with a slight crease, rest it on the bedside table, tent-style, or prop it up with the camera facing out to record your workout, sans tripod. There are, at my count, six basic ways to use it.