The iPhone Duo is designed to be compact, but that hasn’t stopped some from wondering how its size compares with other iPhone models.
Fortunately, we have all the current iPhone devices on hand to show how the Duo, when folded shut, stacks up against the dimensions of everything from the iPhone Air to the iPhone 18 Pro Max. This should give you a better sense of how easily the Duo might fit into a pocket or bag.
The iPhone Duo is a $1,999 phone that, in case it wasn’t obvious from the price, isn’t for everyone. With a 5.4-inch cover screen and 7.6-inch inner display, it serves as a phone-tablet hybrid that’s ideal for multitasking, watching movies and working on the go. The Duo isn’t especially light or thin, but it’s also not too bulky. It measures 5.2 millimeters when unfolded and 11.3mm when folded, and it weighs 254 grams.
As a first-generation device, it has its shortcomings. The Duo doesn’t support FaceID, opting for TouchID instead. Its multitasking capabilities are limited compared to other foldable phones, and the cameras are more scaled back than the iPhone 18 Pro’s. But other details make the Duo feel refined and intuitive, from the matte texture of the inner display that reduces glare to dynamic software integration across both screens. The Duo can be a tempting option for anyone looking for a phone that feels refreshingly different.
Here’s how the iPhone Duo’s size compares to all current iPhone models.
Starting with Apple’s biggest nonfolding phone, the $1,299 iPhone 18 Pro Max has a 6.9-inch display. It measures 8.75mm thick and weighs 249 grams, making it just slightly lighter than the iPhone Duo, though that difference is negligible. What you will notice is how much shorter the Duo is, making it easier to slip into a pocket — even smaller women’s pockets.
Meanwhile, the $1,199 iPhone 18 Pro has a 6.3-inch display and, like its Pro Max counterpart, is 8.75mm thick. The 18 Pro weighs a noticeably lighter 211 grams, so the Duo does start to feel a little more hefty in comparison.
Apple has yet to unveil a baseline iPhone 18 model, which is expected early next year. In the meantime, here’s how the Duo compares to the $899 iPhone 17, which has a 6.3-inch display and measures 7.95mm thick. The iPhone 17 weighs 177 grams, making it significantly lighter than the iPhone Duo.
The $1,099 iPhone Air has a slightly larger 6.5-inch display compared to the iPhone 17. It measures a sleek 5.6mm thick, and it weighs a featherlight 165 grams. If you’re jumping from the Air to the Duo, you’ll definitely feel the biggest difference compared to other current iPhone models.
And finally, the slightly more budget-friendly $699 iPhone 17E has a 6.1-inch display, measuring 7.8mm thick and weighing 169 grams.
If you’re thinking about making the leap to the iPhone Duo, be sure to check out CNET’s in-depth review for more on using Apple’s first foldable phone.
Abrar Al-Heeti
Senior Technology Reporter
Abrar’s interests include phones, streaming, autonomous vehicles, internet trends, entertainment, pop culture and digital accessibility. In addition to her current role, she’s worked for CNET’s video, culture and news teams. She graduated with bachelor’s and master’s degrees in journalism from the University of Illinois at Urbana-Champaign. Though Illinois is home, she now loves San Francisco — steep inclines and all.
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