Last week I got an iPhone Duo. Six days later, I swapped it for an iPhone 18 Pro Max. Here’s my review of the Duo, and why I ultimately decided it wasn’t for me.

I’ve had iPhones since the iPhone 3G in 2008 – almost twenty years now. In that time we’ve seen the screen size increase a lot and the removal of the home button, but the form factor has otherwise stayed the same.

I used to think this was a bit boring. I’d get a new phone, restore it from a backup, and then think “what now?” It wasn’t usually appreciably different than my previous phone, and I felt like I missed the pre-iPhone days when I’d switch form factors all the time to try new things: a Sony Ericsson slab phone, a Samsung flip phone, a Nokia with a truly bonkers keypad layout. I even tried a Windows Mobile phone for a spell.

Because of this I was really excited to get the Duo. The idea of a phone that was new and different sounded great; especially the way it could become a tablet when needed.

However, there were a few downsides for me which I couldn’t really overcome. Ultimately I felt that I could learn to live with them, but if I’m going to drop £2,000 on something I don’t want to feel like I’m making a compromise.

What I liked about it

I really enjoyed it as a developer. I spent a long time getting my app Personal Best ready for the Duo, and it was a lot of fun. My favourite part was Replays, where the interface changes depending on the pose (closed, open landscape, open portrait, laptop, or partly closed). The first time I got to try it out on a real Duo it felt like the first time I made an app all over again. Plus, it was fun trading tips and techniques with friends to get our apps ready.

The big inner screen is lovely, and I especially love the matte finish. It looks almost like magic; a living piece of paper. When I was on the tube here in London it was so nice to have a tablet on me at all times.

The compact shape when closed meant that it easily fit into my pocket. After years of Max-sized phones, this was a big positive. I was also worried that I’d struggle to use it due to being left handed, but I never encountered any problems with that.

StandBy mode was a fun extra. While working I’d prop it up on my desk showing the weather, photos, and a clock.

The outer screen is surprisingly nice to type on as it’s so wide. It’s the perfect width for a good typing experience.

What I didn’t like about it

Touch ID

I really, really missed Face ID. It does such a good job of working seamlessly that I only realised how good it was once I no longer had it. I did get more used to Touch ID as the week went on, but it never stopped feeling like a downgrade. It was especially annoying when the Duo was unfolded as you never quite know what edge the Touch ID sensor is on.

The outer screen

The small screen wasn’t really for me, either. It felt cramped, which seems silly as it’s not that much shorter than a regular iPhone, but I felt constrained every time I used it. And when closed it feels quite dense and heavy, so my fingers would feel fatigued after holding it for a while.

Apps

A lot of apps have been updated to work well with the Duo, but many of them still felt subpar. Some examples of this are Instagram, which works fine but doesn’t make good use of the space at all. X uses a custom tab bar (sigh) which doesn’t move into the horizontal safe area, so you just get a stretched phone layout.

Some of Apple’s own apps adapt to the size really well. Clock is a good example – it switches from a list of alarms to a grid, and tapping on one opens the alarm settings in a popover instead of a new view. Other apps like Messages and Mail switch to a sidebar + detail layout which fill the screen but don’t feel appreciably better than the compact layout. I don’t consider this an indictment of the Duo, more a commendation of how simple-to-use these apps are on compact screens.

Even with time, I’m not convinced that most apps will adapt well to the Duo. It’s a tricky form factor and you need to go through Apple’s Human Interface Guidelines carefully to get everything just right. I spent a lot of time adapting Personal Best, but I’m not confident that your average app will bother to do the work. Can you imagine the likes of Reddit or your average banking app taking the time to do it properly? Not just moving the tab bar to the side, but also the crease avoidance, selectively putting background content into the safe area, and those other small nuances. I just don’t see it happening, but I very much hope to be proven wrong.

I do wonder if iOS changing so drastically for the Duo will be to its detriment in the long term. It never stopped feeling like a slightly worse version of iOS. Moving controls to the sidebar just didn’t feel as natural as having them at the top/bottom of the screen.

Cameras

I missed the telephoto lens.

Choosing

Every time you pick it up you have to decide if you’re going to struggle through using the outer screen, or open it up and use the bigger one. If you’re using the bigger screen you’re committing to using it with two hands, which makes it a little more cumbersome for short tasks where you pick it up to check a notification or send a quick reply to a text.

Is this a small thing? Of course, and it’s a great problem to have. But I have enough anxiety in my life and I didn’t like having an additional source of it, no matter how tiny it was.

Conclusion

The Duo is a great phone. It feels solid. It’s fun to use, like getting an iPhone for the first time again. But it’s just not for me in its current form. With Face ID and some software tweaks, I think it’ll be more compelling and I’d definitely consider it again.

Also as a counterpoint, my partner also got a Duo and loves it, so take my opinion with a pinch of salt. Just because it wasn’t for me, doesn’t mean you won’t love it.

Finally, whether or not you have a Duo, you should check out Personal Best.